I myself instead of contributing to the "rent" want to instead put money strictly into the principal to get it down as much as I can as fast as I can.

Just guessing but you would probably need to refinance the entire property adding the costs of the repairs to the principal assuming you have sufficient equity in the property to cover it.Local community banks and direct mortgage lenders like New American Funding are your best bets to pull it off.

Secondly, some people have recommended just hanging my license under an online virtual brokerage because its the cheapest option and you don't have to give any splits to the principal broker.

Then, following 3yr term of Principal+ Interest payment (no prepayment penalty).

Unless they are a principal broker they do not keep it all and have to split the total commission paid or pay a per transaction fee and so much per month for a desk fee.Given you are out of the country likely on a different time zone there is probably a lot of heavy lifting on a broker/agents part to do this.

Here is a section from my FHA loan (emphasis added):"Borrower shall occupy, establish, and use the Property as Borrower's principal residence within sixty days after the execution of this Security Instrument (or within sixty days of a later sale or transfer of the Property) and shall continue to occupy the Property as Borrower's principal residence for at least one year after the date of occupancy, unless Lender determines that requirement will cause undue hardship for Borrower, or unless extenuating circumstances exist which are beyond Borrower's control.

Does an investor who manages his own rental property need to qualify as a Real Estate Professional (from an IRS perspective) to deduct a portion of his or her principal residence's mortgage payment due to maintaining a home office?

If the house appraised for 20% higher than our principal balance, they would drop the PMI without refinancing.

Exception from rental control Oakland "A rental unit in a residential property that is divided into a maximum of three units, one of which is occupied by the owner of record as his or her principal residence.

The credit union I chose offers both an interest-only HELOC and a principal + interest HELOC.