BS is a pain to fight, but it is certainly not stopping anyone, but since no defender will stop people with medium level, no need to obsess about.
I would TM the fast move of your Snorlax and power up. Having two Blisseys and two Snorlax covers a nice bit of a defender team.
Regarding attacking with Snorlax, you can use him as a general attacker or even against psychics with Lick. It's just slow and there's probably a better option always. I would not power him up for attacking.