I've been a few times but not for the last couple and I know it has grown a lot in the last few years.
I don't think being there for 7am is essential but any more than 30 minutes before doors open you'll end up in quite a large queue but it does go down extremely quickly.
There always seems to be a main game pick from the expo and that does sell out very quickly
Odour wasn't an issue, its a large open space so its not like you are stuck in small room, yes some people unfortunately will stink but unless you're sat next to them it wont be an issue, my issue was people with very large backpacks having very little consideration for others.
Friday is normally very busy, Saturday is an absolute nightmare, Sunday is normally the quietest of the days as a lot of places are out of popular stock items.
The shows can be great I got to attend SU&SD live podcast recording and it was a good show.
You shouldn't find it too difficult finding people other to play with and there is always plenty of tables set up ready for demonstration games too, there are also events that you need to book on to, although that was mainly for RPG sessions based at the Hilton when I went.
As mentioned the food trucks are plentiful but the area can get very busy, there is plenty chain restaurants a short walk away outside the NEC which will still be busy but can be a nice break from the crowds.
The bring and buy is a very big thing and is always busy, it can be a good place for bargains but it can also be an easy way to get ripped off with games with missing or damaged components.