I don't see weight, or body art as a show stopper. Criminal activity is obviously a case by case based issue. This issue I saw toward the end of my time was more of a discipline issue, and I don't think it was recruitment based, but more training and enforcement based. We needed people for awhile, and overlooked some behavior that should have been dealt with more severely.
All in all, the Army can make soldiers, it just needs the latitude to do so when dealing with less then motivated recruits.
Who fights the next war, the next generation, well hopefully, I'm just starting to enjoy civi life...