this is a huge usability step forward. people do not want to accidentally suffer file loss, which is quick to "achieve" with Dolphin's git-menu.

This cache business is absolutely the way to go! :-)

It means that after the "git rm" we can't do a "git checkout" to a branch that existed before deleting the file. A common case.
It seems like it'll make life harder for all users.

IMHO we shouldn't do anything, but if we insist that we should, I would suggest.

don't do --force or --cached

just have the git rm fail, and show a prompt if it does saying to revert first.

Here's another idea: intelligently detect whether the file is in the history already. If not, add --cached so it doesn't bet blown away. If so, just do the rm normally.

What about a dialog that asks the user what to do (--cache, --force, neither) and tell the user what will happen to the file?

In D25431#566479, @elvisangelaccio wrote:

tell the user what will happen to the file?

users MUST be made aware of the danger of irreversible file loss. call the option "nuke my file" if need be. make it abundantly clear even to newbies that they potentially run into FILE LOSS right there and then.