Lololol.
Your theory about Roxas looking like Ven because of memories is funny, because if it were true then Sora's nobody could have also looked like....
Wakka, Tidus, Selphie, Riku, Kairi, Leon,Aerith, Yufiie, Cloud, Donald, Goofy, Cid, Merlin, Malificent, . Do i need to continue?
lol, I never even thought about it that way but, good point.