I don't think you need to worry too much unless you've absolutely burried them, when mine sprouted they would have been fine if they were even deeper. They've got a pretty beefy stem and cotyledons (well, it's not particular fragile or anything) so you should be fine with pushing them in to the media a bit then covering the hole a little, it shouldn't really matter.
It was a while back, so I'm not sure about germination speeds, but I think in the ballpark of 2 weeks (though I could be off!) Some took longer than others. Be sure to give them plenty of room to fillout, otherwise they may have clumped/uneven root systems which may make them prone to tipping over (which doesn't look nice at all, because then you've got a smelly, sticky plant that picks of all of the dirt, lol.)
All I did was (a pretty rough) Gibberillic acid treatment.
Additionally, mine seemed to like it pretty warm and moist (as you may well imagine, but just to give you an idea of my conditions.)