Well,that's what I'm getting at. You have to stop thinking in terms of real life "brains spouting out the back of his head in a fine red mist" logic and start thinking of it in "soot covering face,knocked on his backside,birds chirping around his head" cartoon logic. And that sets up a joke nicely.
Sam: "I have to stop using these cheap bullets. They turn into ash before they even hit the target."
Max: "But they're so cheap,it's like we have an unlimited supply!"
Sam: "An excellent argument for the quantity over quality crowd."
Max: "And with your aim,we couldn't afford the lawyer bills if we let you use the good bullets."
Sam: "Also a frugal point."
Hit a civilian with your car? No problem,he's just knocked down with little stars around his head. You still lose points for that,tho. You just gotta take what's there for SR3 and then just apply something similar in the Sam and Max style.
As for opening doors,well,the thing is,with a little thought,you can open the right doors and not the wrong ones. We do have decades of game making experience to work with here.