Oh man, this is a real broad topic, I feel like we could go on for days about anything in this...

I'm not sure how I feel about the regenerative health in shooters mechanic. It's unrealistic but it's more ideal than punishing you for starting check points for low health. But probably the best shooter I last played was FEAR 2. That game hardly had any regeneration. Only a little, I think. Resistance 1 was similar, and I think combining regenerative health alongside health/armor packs is probably the sweet spot, the best way to go.

Quick Time Events is another controversial one. I'm glad to say this mechanic was one of the "fads" of the current generation, that it's almost died out. It was funny to realize how long Battlefield 3 had been in development, to see a bunch of quick time events in there, something which wasn't even in the (excellent) Bad Company games. I like quick time in God of War, but I don't think I like it hardly elsewhere.

Dealing with the OP's original, I think making you walk off is fine. It's annoying, but it's a part of the game, and something most titles let you use back on your enemies if you're spec'd right. I think throwing controls out of wack would be cool! Especially if you could figure out how the controls have been mixed, which represents you slowly coming back to control...