1) The connection is doable as you only need to clear exit immigration, unless a) Your inbound flight is delayed or 2) Your flight is targeted for intra-schengen passport check, in this case you will clear immigration twice and might not have enough time to make it to your BOS flight.

2) CDG-BOS might have left from Hall K a few times but this doesn't mean it will consistently depart from there. It could depart from either K, L, or M.