Oh well, it is good to get your feet wet if you've been off the market for awhile.
If you decide you like this person, however, you are faced with being honest very early before, I think, things get at all serious. He also deserves that respect since he was pretty upfront with "frequent"
Taking up with someone with an alcohol problem would be a deal breaker for me at this stage. I'm married to one and hope to work it out, but sobriety would be a main criteria in a new partner since I know I would be easily tempted during dating phase.
Good luck!