I would say if the tread wear seems even on the three on the ground, that you do not have an alignment problem with those three. And if the tread wear was even on the one that blew out, you probably don't have an alignment problem on that one either. Maybe it hit a road hazard?
Cannot explain why your tires are showing accelerated wear. They should go many miles before showing any wear. My Transforces have gone about 5,000 miles and show very little wear.
If you have any sort of alignment problem it WILL show up as UNEVEN tire wear. If you don't have uneven tire wear, you don't have an alignment problem.