Love to hear about your group's playthrough! Definitely can be easy to get carried away with the body horror at times haha.
Thank you for flagging some of these rules clarifications! This game is a few years old so there are definitely things I would like to update at some point when I have the time. These sorts of questions/flags are super helpful for that.
In terms of order of ability, all genes will be used in the Resolve phase unless otherwise noted.
For R - I think your interpretation was dead on! Love that it knocked out the player with 2 hp
For Z - correct! This would not be permanent. Essentially whichever of the split abominations is more "healthy" becomes your main one after this turn.
Thanks again! So glad your group had fun playing :)