Hey all, got some questions.

I see in F-Droid that there are "launchers" for android, and they seem to change the appearance of the dashboard.

1. Does a device have to be rooted to use these?
2. Do these replace the original, or can I swap back and forth?
3. Does vanilla Android foul up after one uses these? As in, did it move something around/change something and
4. Would it void my warranty?
5. Can one switch back and forth?

I feel like I have others...