Columbus is fun. I think its the only Midwest city other than Chicago that actually has a thriving gay scene.
Drinks/dinner/socializing: Level, Union Station
It's 18 to get in, 21 to drink in Ohio.
As far as the rest of the city, the whole Short North area (High St.) is very gay and there's always people around.... Gooddale Park has a lot of events and has gay sports leagues.
Ohio State is the largest undergraduate campus in the U.S. and it is just a few miles north on High Street. I would say check their calendar to see what events, plays, sports, speakers, etc. are happening (although during Easter weekend probably not a whole lot.)
Sports, there's the Columbus Crew soccer, Blue Jackets hockey, and Clippers baseball.
Downtown wasn't too exciting, but I didn't really get to explore there a whole lot. It was mainly big office buildings named after insurance companies.
Shopping, Polaris mall is probably where you want to go, or maybe Eastland. You can take a drive by the Abercrombie campus if you're bored.
Like most cities, there are bad areas, but Columbus is pretty safe.
Ohio people are really friendly and know how to have fun. I think you'll have a great time there!