No they're not. If you're not at the front of a crit, it's an accordion at every turn. Yes, you'll be hitting your brakes into each turn and sprinting out of it.

As for the free lap issue, the rules don't state you only get 1 free lap. You are generally afforded the proper amount of time to get the wheel changed correctly then get back into the field. The last time I crashed in a crit, there were about a dozen of us getting wheel changes. With only two guys at neutral support, it took them awhile to get us all sorted. The officials held us there until all of us were ready to get back in at the same time.