Yeah, Like Dan said....you have to cut the top of the spring perch so the air lines can go through the center of the perch. I'ts not that bad as long as you have a big guy there to push down on the control arm...makes it much easier to get the sping in/out. Also, make sure when you do the install, the parking brake is released. If not, it will cause the suspension to stay in the bound state...doesn't make sense that that little cable can hold it that stiff, but it does.
Anyway, after the original install, if you ever break an air line, pop a bag (unlikely), or need to take them out for any reason, they will come out through the space between the spring coils...just make sure they don't have air left in them. My buddy placed my air line in a spot where it made contact with the driver side drive axle, and it wore a hole in the line....so I had to pull my bag to get the line, cut and re-attatched. While I was at it, I put a second schrader valve in. Now each bag is on it's own valve. I HIGHLY RECCOMMEND THIS! If you get ahold of Jason or Tiffany at BMR, they might even send you a free one. They provide great customer service.
As far as the bags bulging; Mine do. One more than the other (I over inflated it...don't ask). But this has not caused any problems. Not only did it help reduce wheel-hop, but the ride has vastly improved from stock with 12-15 lbs of air in them. I usually run 20-25 at the track. Hope this helps.