The Aerospray is amazing for turf war, but kind of stinks (imo) at everything else. Its problem is that - despite it has a fast kill time - it doesn't have much range, so in ranked it gets mowed down by longer range weapons like the Splattershot Pro (which is very popular in Ranked at the moment). Even octobrushes can beat it most of the time due to their range buff.
Curling bomb rush can be really annoying, but it's easy to deal with once you know how.
The mistake a lot of people make while using any bomb rush is acting like they're invincible, meaning that they forge ahead into enemy territory without backup, leaving them very exposed.
Due to the fact that Curling bombs travel across the ground, you can just get to higher ground and splat the person using the bomb rush.
Failing that, on flat ground, as soon as you see the person activate the special, swim right up to them and splat them. This works because they can't throw a curling bomb right at their feet, so any defensively thrown curling bombs will just slide past you, hopefully only damaging you a little. As soon as you get the splat, get away from any remaining curling bombs!
Hope that made sense!