These tenants tend to be reliable and respectful of the space—often more so than the varied guest pool with short-term rentals. 

Are there any reliable software that you guys use for this? 

Having a reliable lender with experience can help guide you to the best options for your qualifications, however at a minimum if trying to qualify for a conventional loan you'll need at least a 620 FICO mid score, other options are FHA using lower scores.

A Minut sensor might be more reliable for detecting smoke presence, keep in mind that it may not differentiate types of smoke.

I think most of what you are asking is impossible for anyone here to reliably answer without more information and you should probably consult an attorney if you think it is worth it.

How do you guys find reliable cash buyers for your deals?

Generally speaking, as long as your daughter has not reached the $13M lifetime gift limit, the gift won't be subject to gift tax.You would want to get a qualified appraisal for the the fair market value at the time of gift/sale, Zillow is not the most reliable :-)

Raising rent on a long-term tenant can be a tricky situation, especially if they’re reliable and you’d like to keep them.

You need to make decisions using the same principles as retailers.One goal of a rental property is to have a reliable income.

But if tenant stability and needing cash flow are higher priorities for you, then it may be worth re-evaluating or looking at alternative properties that offer more reliable cash flow from day one.