The Roxx is a young bar - lots of just legal, or close enough, kids getting drunk... Pretty decent place to pickup, if you're in the right age bracket... If you're 30 or over, you're gonna be way out of place in the joint, though. At least I feel WAY self concious about it... Something about being 10 years older then most everyone else there.
Random Ranch - the country bar a few blocks over (past where the fire was at the other week) - is the most happening place in Barrie these days... Decent age mix (from 19 on up)
Hotels? Nothing really right downtown (well the Simcoe, but I don't know anyone that would actually stay there) - but a few blocks over is the HoJo, couple blocks up, the Travelodge; then in the south end (5-10 minute cab ride away) there's a few choices - Holiday Inn, Comfort Inn, etc)
As for SP's - lots - check here, or in the local papers... Personally, I've used Nite Candy, and been very happy, but the girl I used to see has since gotten out of the business, and with her departure, I've gotten out of the hobby...
Laz