(finally i have an excuse to talk about why the paint roller isnt op)
Is it me, or am I the only one who doesn't find the rollers hard to fend off? Like, at all?
It's only really troublesome to deal with if you don't know how to dispatch them. Once you know to aim at the person wielding the roller rather than at the roller itself, it's pretty easy. The roller's difficulty is pretty deceptive; it absolutely demolishes beginners, is easy to use, and covers the main objective easily. However, once you figure out an effective way to beat them they get pretty easy to stomp.
In a way, they are essentially the Pyro's of this game. They're good at ambushing, they wreck beginners, and they require much more skill when you start going against people who know how to counter them. However, I'm not sure how much the rollers are going to start suffering once you get to a competitive skill level. They don't have the boon of being able to reflect projectiles like Pyro's, but the squid form makes ambushes easier so I don't know.
I'm thinking that they'll start becoming less desirable as skill increases as rollers have to be constantly painting over enemy territory to be 100% effective and this makes setting up good ambushes less likely since you can't stay in a area. It might help to stay in your home area to ambush enemies trying to paint over your stuff, but that goes against what the roller does best; painting rather than defending.
EDIT: Nekoishi brought up to me in response to the last part that you could hide and ambush at the enemy base, even if it is a small splotch. I'd try and argue that it'd be more effective to be painting rather than hiding, but it's a pretty solid argument.
Either way, it's a bit difficult deciphering more than just a vague idea when it comes to competitive viability without at least one competitive tournament being held.