These are some really good points.
FSR's are a bit of a game changer on a slightly larger than speedball field format, because all of the sudden pump or bolt action is a "nerf" in rate of fire but a "buff" in range.
As a super aggressive suicidal pump player, I found the one scenario game I played super boring. I kept running into sniper fire or speedball markers at maximum range. It wasn't until I started loan wolfing away from other players and obvious bunkers that I started to get some kills. So I imagine slinging a FSR of some description would allow aggressive but sneaky play beyond the range of most speedball markers, making a low ROF still relevant when there's 5 high ROF's pointed back at you. Assuming they hear you coming. You know I'm really just in it for the foam melee kills.