typo: temporary

For consistent and precise lingo this would be "KParts plugins" - "KParts" is the name of the framework, and a "KParts" plugin is a plugin for that framework.

In developer and user talk usually "kparts" is used as short form of "KParts plugins" given that it's close to "parts" and what also might have been the root of the framework name. But its not the formal name of such plugins by the framework documentation, so let's better be formal here and also consistent with rest of text.

typo: KParts

"exec command" -> "command line set for the <sometag>Exec</sometag> entry" or similar might be less confusing (and more correct for the casing of Exec). No overview of tags which can be used, by some semantic highlighting might be good to do.

No idea what a good description could be. But this button is used to lock the preview to a given file/document. The preview can still update if the document is changed (control of that is by the other buttons). Instead this toggle button if toggled ensures that if switching the focus to the view of another document in the same Kate window, the preview will not follow to that document, but keep previewing the old document. If switching to another view of the same document, this will not have any effect independent of this button state, as the preview operates per document, not view.

Given that Kate supports multiple views per document, description here might be slightly hard to correctly do. Not sure if that concept of multiple view of the same document is explicitly respected throughout this manual and if which terms/lingo is used then.

But the currently proposed text might be misunderstandable I fear,