would you be okay with someone else taking over the patch and finishing it off?

Thanks for the patch. I like the feature but there is something missing: if the next file is out of the visible view, the view doesn't scroll and the rename operation gets canceled.

Added support for feature 269987.

but I have one behavioral request: could this feature be implemented for Icons view as well? Right now it only appears to work in Compact and Details views.

I feel that we are splitting hairs. Do as you think will be best.

It doesn't matter whether or not the whole filename is currently selected; the keys should always have the same behavior.

This should happen whether or not the text is currently selected.

I can't see it in bug report. Anyway it can be done in other ways right now. I just don't see the point for it to work this way.

It's about trade off between usability and consistency.
Kate does what it does to be able to select whole, very long line.

Added support for shift+home text selection.