Tucson's vibe is relaxed and the people are nice. It's a liberal city in a sea of red, and it's quite diverse and culture-rich. If you plan to live and mostly stay within a thirty-minute walk of campus, a car is nice, but not necessary. If you are going to live farther than that, I would recommend getting a car. The food is some of the best, and you can find cuisines from all over the world. In fact, UNESCO gave Tucson the title of the United States's first capital of gastronomy in 2015. Tucson is, indeed, hot, but if you have air conditioning and keep a bottle of water with you, it's manageable. I've only seen one (dead) roach since I moved here, in my apartment parking lot.
I live in the beautiful Sam Hughes neighborhood, and it's my favorite place in Tucson. There are lots of restaurants and little shops in the neighborhood, and lots of places to walk my dogs. The neighborhood is clean, quiet, and very safe. My neighbor even leaves his car windows open when he parks his car and he has had no problems with thieves or vandals. My apartment is a thirty-minute walk or a ten-minute drive to U of A. I don't have a bike right now, but I'm guessing the ride would be about ten or fifteen minutes. Some of the apartments in Sam Hughes are expensive, but there are cheap options as well. I pay $550 a month for my 550 square foot one-bedroom apartment.
I work up in Casas Adobes, and it's clean, quiet, and safe there too, but it takes me at least half an hour to drive to campus from there. Also, there isn't as much to do there and housing is generally more expensive. It's more conservative than Tucson and has an older population. Southern Tucson is mostly Hispanic. It has a bad reputation, but the areas I've been to so far down there feel safe and clean. In all parts of this region, crime varies from neighborhood to neighborhood. Not all of South Tucson is dangerous and not all of the areas North of Tucson are safe, so it's imperative to check out the particular area you want to live in.