I think I like Zack too much to write him. That, and yeah--no clear picture of him, other than other people's.
I'm running into a problem now, with Reno, where the Reno from TTYNKAP is too engrained in me--it's hard to try to NOT write him with that background, y'know?
As for the clones, I'm actually kind of looking forward to writing them--something about how very fractured they are. And Seph, well, I've been itching to write Seph since I read the words to "Wu shuang" (the last Jay Chou song I sent you) and saw how much that song fit Seph. So, yeah. Writing Seph is coming sooner rather than later. Because, you know. Dude. Sephiroth.