It is difficult to invent a good chess variant. My show, ChessWhiz TV, typically streams a new chess variant every week, and most of them are not that great! :)
See
www.youtube.com/c/chesswhiztv for previous episodes.
Responding to the ideas here:
#1 Power Chess would be the same as 5-checks chess, because reaching the other side of the board is too difficult without being checked.
#11 Insane Asylum Chess would probably last too long, since the board would stay full. Usually chess games reach an end as the board becomes more empty.
If you want to invent a variant, find a friend and do a LOT of testing. If you post your idea without trying it first, it may not work too well, haha. Did you know that Horde Chess was updated after it was launched to make it more balanced?
Anyway, we have 4 more variants coming up soon on our Sunday broadcasts: Alphabet Chess, Entourage Chess, File Extinction Chess, and Mano-a-Mano Chess. Here's the events calendar with more info:
http://chesswhiz.tv/calendarGood luck! :)