It isn't that Denver isn't a safe city - just like everywhere else you need to watch your surroundings. The incidents happened last weekend and since then nothing else. I think like a lot of campuses, something will happen, everyone worries, the worry goes away, something happens, repeat cycle.
As far as the living facilities on campus - I have no idea. I haven't seen them. They might have pictures?
Aurora probably isn't where you are going to want to live. It is fairly far away from DU and depending on where in Aurora you live (it is a fairly big area), you can either live in a really good area or a really, really bad area. When you are looking, you probably want to look at the prices of the places you are looking at - if they are "cheap" then they probably are not in a great area. The Washington Park area (near DU) is really nice from what I know, but a little pricey. Capital Hill/Cheesman Park is closer to downtown and about halfway between each. The area is about 15 minutes (depending on traffic) from DU. The area around the university is probably your best bet depending on whether you are going to have a car or not. Also, that way you are close to school the first year and get to know the city a little bit and then can decide where you want to live the second year.