In regard to BL being its own tier, it already is in the most literal sense. I assume you mean that it should have its own metagame, to which I would respond that it would be very unstable. The only thing that can take any kind of special hit is Regice, which still loses to most any special attacker in the tier. The physical side is a little better with the likes of Slowbro and Tangrowth, but they are still pretty easy to get around. I've played a few BL matches before, and I threw together 6 random sweepers and didn't lose a game. It's just way too shaky to actually have a serious metagame. It's cool for fun, but otherwise, it won't really work.
Also, Staraptor cannot be stopped. Period. It would basically be revenge killing to the max but to a awfully excessive extent. There's nowhere to post my opinion so I thought I'd post it here, but yeah. BL isn't like other tiers besides ubers at all, so it probably shouldn't be treated like them. Even ubers can at least run a functional metagame, whereas BL doesn't take a whole lot of skill to win at.
Though for a change of pace, BL battles aren't so bad. "Use Magmortar and Staraptor" will win you most any game, but it can be fun.