Regarding (1), that's on your keyboard, which you can choose. Maybe you can give Futo a try? https://keyboard.futo.org/

Why does it need its own F-droid repo?

Because the code is not provided under a free/open-source license, and therefore does not meet the requirements for the main F-droid repo.

Ah interesting. They use the "FUTO source first" license. https://github.com/futo-org/android-keyboard/blob/master/LIC...

Open source with limitations on commercial use.

Technically it's "source-available", not "open-source".

Simple Keyboard is on F-Droid too. Supports moving cursor via space bar.

Same for HeliBoard