Good so far, but keep in mind that if Harry doesn't go to Hogwarts, Hermione is probably going to get either killed or maimed by the troll on Halloween, and then either Dumbles has to either move the stone, or someone else has to save it. Then, assuming that Voldie doesn't get the stone, someone has to save Ginny from the Chamber the next year. If she dies down there, you have to deal with either 2 Voldemorts, or reintegrateing the older spirit into the new younger body. My suggestion is to have someone else save the two girls, (probably Ron, or Neville, as they're the only ones that are both brave and stupid enough to do it with Harry gone.) otherwise, you have Voldemort way too early in your plotline, and the Tri-Wizard won't happen. Of course, if Hermione is only injured by the troll, she could tranfer to Beauxbatons with a language charm.
As for your questions;
1)fade to black scenes alway seem to be incomplete to me, but only write the lemon if you feel comfortable doing it, and can do it well.
2)Fleur is 3 years older than Harry, so that's gonna be tricky. I'd say nothing past 2nd base before he's at least 13, and no sex until he's 16.
3)Harry's already overpowered compared to his year-mates that are at Hogwarts, but given what you've written here, with training, he could probably manage animagi or metamorphmagi by 3rd year, and parselmagic by 4th. Some hints of weak Veela magic might be feasible by 3rd year, if you can come up with a good explaination for it leaking through their betrothal bond.
4)Aside from political posturing from Dumbles about which school Harry's going to go to, I'd think that Harry's first two years of school would be fairly uneventful. I'm sure there will be some increased security when Sirius breaks out of Azkaban, but I'd make up some people to take the place of Malfoy and Ron. He needs a buddy and a baddie.
Okay, I've rambled long long enough, and haven't spell checked this. Looking forward to more.