It's the move that really hurts your pride and most people waste Rapid Cancels on.
I'd have to say most of what you said is right except Overhead Cloud...it's too high to be dispelled unless you dispell it early with j2C or jD.
Haku can either sword swing or use D moves to null anything that's a projectile, but more than that, he can Null AND Grab so staying away from him might not be a bad idea...but Haku thrives on predictability and patterns. He'll being doing his best to read you like a book. I've punished air and ground Arakune strings if they come near me, and since most Arakune's don't like dealing with pressure (especially Haku pressure), they tend to fall back into old habits.
Even cursed, if you have bug patterns, Haku will try to read them, he can use stuff like 2C to deal with your D Bug if timed right, and if you didn't know Haku's sword guard moves don't do a thing to Guard Libra.
j.2C can handle Bell Bug, and since IAD is Haku's thing, you won't be able to just plain escape. Your best bet is to hope for jumping crossups and shield cloud, while working on 2D spit games, but even that's predictable and not guaranteed.
Haku's 5D can null both hits of 2D spit if he times it right. His 2B, 5B, and jB have fuzzy guard so if he throws that out instead of jC or j2C you might need to rethink what he's going to do.
If you do get a successful Overhead Cloud though, you actually might want to use that in your favor since you can pretty much guess he's not going to jump into that. But he will use his rush moves on you or just plain hop after you and hop moves can hide instant Overhead if you're not careful.