I currently live in Detroit and have lived in several different areas within the city, including downtown. The area you’re staying in is safe.
Within a few blocks of you are high end restaurants and bars, hotels, the winter market and Christmas tree, and stores (including Gucci and and Shinoa) and a heavily guarded FBI building is visible from your hotel.
You’re staying not far from where major events have taken place including the NFL draft as well as large music festivals which have attracted millions of people to the city, in addition to the regular sports games that bring in tourism. Downtown has very much shifted to cater towards visitors and getting people to stay and spend money.
As others have said, midtown also has a lot to offer including the DIA. Eastern Market can be fun on the weekends but in the winter it’s less active. The surrounding metro area also has things like Greenfield Village and the Ford museum depending on what kinds of things you’re interested in.
Will you see homeless folks and potentially asked if you have spare change? Yes, it’s a bigger city in America. Will you be attacked by exploring the downtown area? No.
If you want any specific recommendations please let me know and I’d be happy to help.