Yes, probably it will be forced, but atleast it could be tested.
I've spend many hours on my config for cod4, there is nothing wrong about changing a config :P
I didnt played infinite warfare, i dont like the future stuff. :/
MWR is realy bad if you compare it to the original cod4, but atleast its a little bit more active.
You are right, no mods and that wont change. Thats why MWR will die quickyl.