About 12 permanent beers and 8-10 rotating ones.
They have a rotating tap because some beers are seasonal. But it's roughly 15-20
Lots!
A lot
There's enough to keep you busy, specially if you get half pints or a flight. I agree with Ezekiel on the quantity on any given day. Bartenders are helpful, and you really can't go wrong, even if you picked blind.
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