Once the A hits on the turn then I think you are right in trusting it to be good.

However until the fishies have identified themselves (or got knockedout) I don't like the continuation bet on the flop as it kind of rules out any decent holding (you wouldn't lead with AK, KK, AA or trips) so tells your opponent you have nothing. If you check the flop, you get to see what he does and make a move on the turn and then if appropriate more effectively represent strength based on your preflop bet and the checked flop (being out of position here is a big disadvantage). Though as I say I wouldn't bank on your opponent being aware enough or good enough to fold anyway.

Personally I'd have called preflop with that many people in and hoped for a beast of a flop and pretty much let it go otherwise. You can't win a SnG in th first hand but you can lose it easily.

This probably seems contradictory to the other advice about more aggression, but later in a SnG I'll be sticking all my chips in the middle with nothing at all if the situation demands. But context is everything and here you have everything against you with AJ preflop - lot of people in the pot, out of position, it's quite possibly behind already to small pairs and the only way you are going to win a really big pot is by getting really lucky, as not only will you need to catch a card, so will your opponent. This leaves you with very few flops that will get you action where you are ahead (probably jack high versus J with a worse kicker or flush or straight draws). Basically right idea, wrong time. I'm sick as a dog today so I hope that makes sense