Overall, these changes are sensitive and go with the times. I don't particularly like a dock on the left, but allowing this feature is good IMHO. Others like icons-only, I am all for.

While in Panel Edit Mode, use buttons to determine screen edge rather than making the user manually drag the panel

Please do not forget, that we can drag the panels also to other monitors, so this should be possible with buttons too.

While in Panel Edit Mode, use buttons to determine screen edge rather than making the user manually drag the panel

I think this should not be changed as I think the existing drag action is an intuitive and elegant solution as opposed to a bunch of buttons or a submenu.
However, there should be a clear indicator you have to drag with the button, like a hover text (maybe that could also appear when you click the surface without dragging it) and an icon like transform-move displayed alongside the drag surface.

I think the other changes are quite sensible.

The transform-move icon:

In T10047#167528, @trickyricky26 wrote:

While in Panel Edit Mode, use buttons to determine screen edge rather than making the user manually drag the panel

I think this should not be changed as I think the existing drag action is an intuitive and elegant solution as opposed to a bunch of buttons or a submenu.
However, there should be a clear indicator you have to drag with the button, like a hover text (maybe that could also appear when you click the surface without dragging it) and an icon like transform-move displayed alongside the drag surface.

I think the other changes are quite sensible.

The transform-move icon:

I agree, an icon is sorely needed. When I tried to move the panel for the first time 2 years ago, I couldn't figure out how to do it because the "Screen Edge" button didn't seem to do anything. As a method for moving panels around, it works, but there's nothing about the button that says "Drag me!". The Width button could use an icon as well.

Would it help if "Alternatives" got renamed to "Alternative Widgets"?
It already says that in the title of the alternatives popup.

Can D17323 and D17321 be landed?

In T10047#170029, @GB_2 wrote:

Can D17323 and D17321 be landed?

I'd really like some Plasma people to approve first.

Just a thought: since "alternatives" pattern seems to work, what if Bob find as alternative to application launcher (Kick off) a full screen launcher like the GNOME one, that:

• list favorited apps on the left, with a button to show all apps in categories in the middle of the screen
• show current windows in the middle of the screen (like Present Window) by default
• list virtual desktop on the right like GNOME with the capability to move windows there
• show a focused search box at the top so if the user start to type windows are filtered (like in Present Window) and KRunner results are shown too

This is the UX more similar to the GNOME one (starting this menu with meta/windows button should work too, like in GNOME) that I can think using Plasma concepts.

what about latte dock? it's amazing for mac converts (myself included) - is there any way to include it in/with plasma? it provides a true mac-like dock experience

In T10047#174107, @alex-l wrote:

Just a thought: since "alternatives" pattern seems to work, what if Bob find as alternative to application launcher (Kick off) a full screen launcher like the GNOME one, that:

• list favorited apps on the left, with a button to show all apps in categories in the middle of the screen
• show current windows in the middle of the screen (like Present Window) by default
• list virtual desktop on the right like GNOME with the capability to move windows there
• show a focused search box at the top so if the user start to type windows are filtered (like in Present Window) and KRunner results are shown too
  
  This is the UX more similar to the GNOME one (starting this menu with meta/windows button should work too, like in GNOME) that I can think using Plasma concepts.

Yep, agreed. However Bob wasn't looking for a dashboard UI; he very explicitly wanted a "Dock" on the left.

@ngraham wrote:

• Bob right-clicks on empty area of panel and sees "Alternatives..." It does not occur to him to click on it.

When moving to another OS, I would avoid to click on buttons with "...", until I know what will happen. I would fear something like Internet Explorer popping up and loading a Bing search for "Alternatives".

Additionally, "..." indicates to close all menus, so these items are always my last I try.

I suggest to name it Alternatives to “Task Manager”, and to make it a submenu which holds all the alternatives as radio button list, instead of opening a new widget. (There could be an item "Show all...", which opens this widget.)

There could be a menu item “Help...”, which explains all the terms like Panel, Widget, Launcher, Task Manager, System Tray,... It could just open Help Center -> Plasma Manual -> Using Plasma (-> The Panel). There would be a screenshot like this:

In T10047#174132, @ngraham wrote:

Yep, agreed. However Bob wasn't looking for a dashboard UI; he very explicitly wanted a "Dock" on the left.

with or without a top/finder bar?

In T10047#175270, @rooty wrote:

In T10047#174132, @ngraham wrote:

Yep, agreed. However Bob wasn't looking for a dashboard UI; he very explicitly wanted a "Dock" on the left.

with or without a top/finder bar?

Didn't seem to be a high priority. The first thing he wanted was a left Dock/IOTM. It's possible he would have wanted a top bar too, since that's that GNOME has and he was fairly well accustomed to GNOME's UI.

In T10047#175270, @rooty wrote:

In T10047#174132, @ngraham wrote:

Yep, agreed. However Bob wasn't looking for a dashboard UI; he very explicitly wanted a "Dock" on the left.

with or without a top/finder bar?

That would be Add Panel -> Application Menu Bar, right?

Radically improve the UX for switching between common panel UIs (e.g. Windows XP style task var vs Dock). This probably needs its own Phab task.

There's now a plasma widget that does just this (video).

Zorin OS (a GNOME Shell based distro) also has something similar we could draw inspiration from:

I think the task should be expanded to include their accent picker, and auto-theme features as well:

Thankfully we have Look-And-Feel packages that can do this. What's needed is for someone (maybe a new "KDE VDG" account?) to publish some minimal LNF packages for Windows, Mac, and Unity style layouts. There are already a few that do this on store.kde.org, but they change everything else too, not just the panel layout and task manager. Maybe we could even put them in a new repo (plasma-workspace-look-and-feel-extras)? So that distros could easily ship with them? Or we could put them in the existing kdeplasma-extras repo.

I wasn't aware of the widget which is very interesting. I came to add that Feren OS Next is using Plasma and includes a theme tool that might also be worth taking a look at. It includes the ability to apply layouts as part of switching a theme. Also, MATE Tweak has a layout feature that provides packaged layouts that make changing them quite simple.

I'd like to step in here if it's fine. I've been working on Feren OS Next, a Plasma-using Ubuntu Distribution that aims to do multiple things. One of those things happens to be providing a more-complete Look & Feel layout application process which affects more than what it currently does.
Examples of things it also affects includes:

• The current Latte Dock layout being used
• The titlebar buttons layout in both KWin and GTK Headerbars (when used in conjunction with an XSettings Daemon like the one Feren OS Next uses, otherwise only KWin is affected)
• The applied GTK 2 and 3 theme
• The icon set applied to GTK 2 and 3 Applications to add consistency
• The cursor theme applied to GTK 2 and 3 Applications for the same reason
• Whether titlebars are hidden on maximise
• Whether to assign Meta input to Latte Dock or Plasmashell (this was before I found out that Latte Dock made that an option in their Settings window)
• More

I've put a GitHub up for the source code if anyone's interested, outside of the XSettings Daemon as that's not something you people will probably be interested in given Plasma Wayland seems to apply GTK Themes on-the-fly now, at least for me anyway...
https://github.com/feren-OS/Themer-Plasma

If this can be of any help for you on your quest to make this a thing, I'd be more than happy to see some of the concepts used here be used upstream in KDE Plasma.

Thanks for the explanation @The-Feren-OS-Dev, this is tangentially related you might be interested in T11052 as well

Has anyone ever suggested hiding windows when editing the panel?
When moving plasmoids can happen that you move them outside the panel putting them on the desktop and you don't even notice it.

In T10047#175129, @davidhurka wrote:

There could be a menu item “Help...”, which explains all the terms like Panel, Widget, Launcher, Task Manager, System Tray,... It could just open Help Center -> Plasma Manual -> Using Plasma (-> The Panel). There would be a screenshot like this:

Even in my mother tongue I didn’t know what exactly the “Systemabschnitt der Kontrollleiste” (System Tray) is. Everything could be related to the system...

I think that if you have to explain it, it's not clear enough.
The Feren OS approach is the right direction to take.
Hide all the 'advanced' settings and let the user choose from a layout when logging in for the first time.
I'm trying to convince friend and colleagues (that already use linux) to switch to KDE Plasma but everytime I get stucked in explaining "how to add an app to the panel".
Actually you have to choose from:

• Add to desktop
• Add to panel (object)
• Pin to app bar (icon only process manager)
• Add to favorites
• Try to drag the icon from Application launcher to the panel
• ....