A real easy way around Zappa's Ghost Summon is:
1) If he tries any low pokes (which honestly would be stupid), you can easily poke him with K, 2K, or 2HS. Trust when I say his 2S, is not a good poke.
2) His best pokes are on the top which would be Far S, you can simply 6P into an IAD or dash in for a Mist finer combo.
3) If you have a lvl 2 MF, as soon as he releases his ghost, just hit him with it.
4) If he is playing the "I'm a mid-air cunt throwing down the ghosts game", 2 things that I do is either 236 P each ghost, or IB each ghost going up to him and then throw him.
5) The great thing about when he tries to pressure you is that if he has to run in the ghost have to delay. A more experienced Zappa would 5K, 2K, or 5P which the usually pokes can handle.
6) A great thing also that works like a charm is that if you 2D him you can hit him with 2 coins instead of one. Which is great for the fact that if he decides to rush in with the haunted "rock", the Mist finer deflects the rock and hits him for easy damage.
The greatest advantage I believe he has is if he 2Ds you into 236 P, he can easily go high or low (and his 6P goes right through the OD). That is about the only thing you really would have to worry about honestly. When he is throwing all the ghosts around you can just take them apart one by one. I personally don't have a problem dodging them so I don't know about being locked down by him.