Hiring someone to do the work will likely cost too much (I would charge a small fortune, it's an incredible amount of work) and doing things as cheaply as possible will bite you in the *** later when you start having issues with your own shoddy work and/or materials.

You will also quickly learn how to manage properties well instead of spending decades figuring it out like most investors.

I would like to surf the BP app whenever I have downtime just to get my daily news updates on real estate and take advantage of the PRO articles.Someone help!

The more common one is a flat value for the ADU, like they would for a pool or another bonus.

There are also a large number of accountants we work with who say that as long as it is done at arms length as a business like transaction then they are fine with it. 

I recommend you go to the source and educate yourself on all the landlord-tenant laws, particularly in an increasingly regulated state like Colorado.Here's a good starting point: https://doh.colorado.gov/landlord-rights-and-responsibilitie...

Commercial liability will only cover liabilities like lawsuits right?

I was hoping to hear you add something like this...  

Insurance costs are going up like crazy.

Would highly recommend @Keith Mintz for this case, he knows San Diego like the back of his hand.