The 'I want to meet you' line implies quite a bit more intimacy, but some of that appears to be lost when you translate it to English, y'know? I suppose it could be both, because she always was trying to help him--but she was also quite interested romantically as well.

It's not that she didn't have any feelings towards Zack--but rather grew out of her crush. She states explicitly in the novella that she loves Cloud much more than she had ever loved Zack, and rebuffs him when he flirts at her, basically telling him that someone who has been friendly with many women can never become a good lover. XD I'd feel bad for Zack, except he takes it in stride and seems to be doing the flirting thing more for old time's sake rather than seriousness.

The weird thing about the Lifestream though, is that Zack only woke up from the Lifestream when Aerith was remembering how Cloud walked and gestured--since those were the things Cloud had taken from Zack--Zack recognized the image and woke up--so the cameo at the end of AC was more to be there for Cloud after he finally lets go of his guilt, rather than to imply 'HAI THAR, I TOOK AERITH BACK, KTHXBAI'.

I'm just getting you up to date is all, I hope you don't think I'm being rude! ;_;