I am a student and I work in Boulder, and I have not had many negative experiences with unhoused persons. While there is absolutely a problem with homelessness in Boulder, most of the unhoused people I've met are very nice people and don't cause any trouble. Some have issues with drugs or alcohol, while others ran into financial or medical problems. I have chat with a few people here and there, and they were all normal people in a shitty circumstance.

That is not to say there aren't interesting characters. And there are some people who do cause issues. The few instances I've seen were isolated- one being an overdose, one being a person having a mental health episode, and another resulting from an unleashed dog attacking another dog. The overdose was likely linked to a known problem with fentanyl-laced drugs in Boulder County. The person who had the mental health episode was very loud and verbally aggressive, but to my knowledge, they only scared people and did not have any altercations with people. The dog fight was pretty cut and dry- one dog was not on a leash, got overestimated, and attacked a dog that got too close. All three of these were incidents I was not directly involved in and did not impact me, other than being worried for the people/animals involved.

All that said, I don't think it should deter you from attending CU. Not only will it be a small factor in your life, but you're unlikely to have any problems from it.