I would say controlling fs and cs would be easier.... because a lot of new players might be thrown off by pushing a button and having it do 2 different attacks, I mean they don't even use the 6. but that's more of a reliability thing for new players rather than an actual difficulty decrease.
also the way otg's work (or more accurately don't) is kind of wierd to get used to, it can be hard to determine when the enemy is technically considered "down".
but those aren't really "difficult" just take getting used to.
realistically though FRC's are a little hard to change, it might make certain links tougher, or might open up links that weren't previously possible. Maybe if they changed the effects of an FRC, like buffers, or something, if might be easier, becuase 6frc6 and FRCIAD are rather annoying....