Alright, I've reached an exciting point in developing this game—it's "stable"!
My friend and I tested the changes I made yesterday, and all the rules work out really well! Giving the low cards a bonus plus making them heal provides a really interesting power balance. If you happen to have Ace–3 of one suit, that's great, but it goes to waste if your HP isn't low enough, but every turn that you're holding them prevents you from getting a super strong attack saved up!
I also specifically tested out the attack bonus on the low armor, and it works pretty well too. It's not too great an advantage that it breaks the game, but it really feels better knowing that you have compensation for having low/no armor if you're lucky enough to have the proper suit to use it while at the same time being a truly disadvantageous enough situation that (most) players wouldn't actively forego having armor just for the attack bonus.
My friend and I are going to try to play the game with some other friends over the weekend to see how the rules hold up against other people, but other than that, I'm calling this game done! I won't submit it until after we've been able to play a few more times, but I don't plan on making any more big changes—maybe just occasional little tweaks to improve situations we might have missed earlier.
Anyway, yeah! I do have the game page up at least, so if you're interested in checking it out in all its iterations before I submit it, here it is! :D