I've used both PS4 and Ps5 controllers. You don't need to do anything except to plug it in.
I've only had issues in one game (Minishoot Adventures), where the solution was to disable controller support layer that steam comes with.
I haven't tried Bluetooth, as I don't mind the cable.
What do you mean? If there are no guns... what... what would the shootings be done with? Fingerguns don't count.
As for an example that comes close to what you're asking for:
There is no silver bullet here tho. There are some pretty obvious directions that would improve things, and some that would make it worse. Adding more guns, is an amazingly stupid approach, and characteristically American. If adding guns makes things worse, could reducing guns help? Surprisedpikachu.
Gotta defend yourself against people with guns, with guns, so make it more accessible. Give gammy a gun, you never know! How about littly Timmy, he's old enough to walk home... ah, that's right, there is no infrastructure for walking. That'd be too dangerous.... Meh. Enough Internet for today.