My partner isn't willing to bring any funds in just yet (he's very skeptical) but he was willing to be added to the title in an attempt to obtain a higher line of credit. 

Now that funding fee can be added to your loan as well if you don't want to pay out of pocket.

We opened up the floor plan, added 1 bedroom and 1 bath to the main house and will be adding another bedroom to the second unit.

My lease does state if someone is staying past 14 days and over 18 will be added to lease.

The ADU laws were coming out at a quick rate until the start of 2020.By state law, ADUs can be added to zoned multi family.  

There's a lot of value that can be added to a project if you are able to take one large building and divide it up. 

Other than that, you should be adding the fees to the tenant ledger and then taking appropriate action. 

In your case, the co-signer will be added to the mortgage and their income and credit score will be used as security against the loan.If you're fortunate to have this option, I would speak to as many lenders as possible to determine the best financing avenue for you and your potential co-signer.

If the mechanic currently has a policy, as to be added as an AI and you can allow him to come on the property.The lessors General Liability would be in addition to what the tenant has to protect both parties. 

So tax liability would be added to earned income for the year.