If by the 401k plan, then the 401k plan can get a non-recourse loan.

If you used the refinance proceeds to buy a new car and pay for a trip to Disney World, then the mortgage interest is a non-deductible personal expense.

With the signed letter from her, will LTB agree that her rent is $650, and can we evict her due to non-payment of rent?

Reassessment would be ... undesirable.There's also a bulletin posted on the DRE site (from 2016) that talks about this subject as it relates to short term rentals (but they cover all mgmt cases):http://www.dre.ca.gov/files/pdf/adv/LicenseeAlert2...The "power of attorney" thing has an ominous "don't use these provisions to circumvent the requirement" clause. 

It's a slower process building your business credit reports for non PG credit.

@Matthew WardYou are correct - Florida does not have an income tax on individuals.If you operate out of state - a portion of your income may be sourced to a different state.You may be required to file a non-resident state return in that state.The Federal tax return reports income that you earned from worldwide sources.

If the tenant "abandons" the unit based upon facts (no notice in writing, but all non-trash personal property removed, utility changed billing, , etc.), I advise writing a "Notice of Abandonment" letter to the tenant that is mailed and emailed to last known address. 

You want two or three Architects on file since they can be busy if they are good and you need one when you need one not a year from now.

Some were filed that same day, the day before, two days prior, etc. 

@Warren BranumA Death Certificate is going to need to be filed.