I don't believe there is a common practice, its going to be dependent on local standards.

Many investors from California, are choosing to invest in the midwest because of the yearly returns making more sense in these lower priced markets.

It depends partially on your local PHA, but mostly on whether she is currently on a Section 8 voucher (and her rent has just stagnated) or has she just received one she is intending to use on her current unit?

Depending on how smart they are, or how helpful they are.

Depending on what campus you are near will make a huge difference and even more so, how close.

Most financially independent, wealthy people get there through hard work, sacrifice, and time.Spend 2-3 months learning how to analyze properties, cut expenses, increase income, and save up as though your life depended on it.

Ultimately, trust your instincts and choose a property manager who demonstrates professionalism, integrity, and a commitment to maximizing the value of your investment.

Given that it's an ADU and you are an owner occupant I would courteously terminate the lease (the how on this is going to depend on your local laws and your lease) and get a new tenant ASAP.

I believe in many circumstances a permit or use license will be required by the municipality depending on the use. 

If they treat you like the existing owner:The tenants would pay between 1st and 5th give or take (depending on local laws about when rent’s really “due”.