This is a classic scenario of too much trim 'in'. Only when that has been discounted is it worth looking elsewhere. The trim tab will not change the tendency to roll, only the steering torque will change. The prop, whilst more likely to cavitate, may lose some speed, and vibrate a bit more, again, won't cause it. (The most efficient prop theoretically only has 1 blade
So I'm not saying it can only be lack of engine trim, just that IMHO it's most likely to be..
I bet the boat feels like it's trying to crab sideways too.