Done a lot of road trips, 36 stadiums and a new one this summer (planning Mil/ChiSox/Cubs games in late July in 3 nights and maybe the Jays at Cleveland in August)
Detroit: Ford and Comerica are across the street from each other, so you can plan multiple games during the fall on a weekend. Many hotels and casinos within decent walking distance of the stadium. Greektown is a few blocks away, one of the best restaurant strips for big eaters. The Hilton Garden Inn has been my stay about a dozen times over the years, right between the stadiums and Greektown. Safety isn't really an issue with common sense. This area is a ghost town for most of the day until the sports crowds invade. Little is open on Sunday mornings, or at least wasn't the last time 2 years ago.
Cleveland: Hotels and restaurants abound within a mile of the stadium. Usual haunt is the Radisson Gateway for a half dozen road trips. This area is more alive than Detroit's, but still a ghost town until restaurants open around 3-5 pm. Safety not an issue with common sense. Quicken Loans Arena for concerts and Cavs right across the street from the Radisson and other good road trip hotels/motels.
Pittsburgh: Best stadium easily. Usually stay at the Renaissance and walk the 1/4 mile to the bridge to the stadium. Half mile walk to Heinz Field. A higher living standard in this area than the other two cities, fine dining and cultural events nearby. Go see the Warhol Museum and try to chat up the curators between games.
Enjoy!