On the EPs, it's All Eleven All the Time, Baby! (I should really get this on a tee shirt, but likely no one but me would ever know what it means...) Besides enjoying having all of them always available, on a Steam install there are no convenient ways to suppress any of them once they are installed. But yes, one's system does need to be strong enough to be up to the task.
How to maintain smooth gameplay involves a lot of different things and will differ greatly according to system strength and play style. But perhaps this page helps?
https://www.nraas.net/community/TIPS-FOR-BETTER-GAME-PERFORMANCE
(newly updated and reformatted for easier reading)
