It would cost a very very very very very VERY small amount more to run the Timer, I believe, I haven’t tested it, and that’s based on the idea that you’re doing 1 divided by 60 each time, fixable by replacing it with .16.
Yes, fighting games do, which is why they didn’t release on PC for so long(due to the variable equipment it’s working with). They are tied to framerate, so if the framerate goes down, the game physically slows down- not something you want in an action game or RPG. Basically this comes down to the production design for the game itself- Monster Hunter, Capcom’s OTHER big one, follows the opposite path of frame independence and fluidity, probably because of the PVE nature instead of Street Fighter’s focus on PVP and exactness.
Kind of, yes. It attempts to run tick every frame. It’s for trying to simulate an “All the time”, or “Constant” thing, which can become costly if the thing can run fewer times for the same effect.