You can do a lot worse than walking around downtown. Restaurants and bars are clustered: E. 4th has a lot of good eats, as does the Warehouse District (W.9 and W. 6th @ Superior and St. Clair). Look for the building with the knife through the corner.
One weird thing about Cleveland: the numbered streets are north south, and W. 6th doesn't intersect with E. 6th. They are numbered based on how many blocks east or west of public square they are. That can be confusing, or it was to me when I first moved to Ohio.
I have been in several of the downtown hotels but never stayed in them. The conference facilities seemed nice! You get what you pay for, is my guess. The Hyatt at the Arcade is in one of the coolest buildings downtown. It's less than a mile to the stadium from the downtown hotels. Downtown is pretty safe even at night, other than occasional aggressive panhandlers. Check out the Flats East Bank project to, which has a hotel and several restaurants (Ken Stewart's: thumbs up but pricey; I think it is open by now).
If you venture out of downtown, head to Ohio City, which is immediately to the west of downtown just across the river. A neighborhood that will feel familiar to Rochesterians along W. 25th, with excellent food choices at a variety of prices and 3 great beer places (including the Great Lakes Brewery restaurant and brewery). Also recommend Momocho for modern Mexican, at the north end of W. 25th. Also, go to the Westside Market at W 25 and Lorain. A true old-style urban market.
Cleveland has great food, I will say that. And there is a casino right downtown, if that is your thing.