If you have a home office you use for your rental company and you go driving for dollars, can you claim the standard mileage deduction?

Consider all the factors and pick the best one.

Vacancy is the final factor...and the hardest to determine. 

With either you should look into good sound isolationYour revenue after debt service doesn't factor in maintenance, capital expenses, vacancy, possible construction cost overruns or delays.

And LA is a 4 hour drive (45 minute flight) from LA.  

What's important to note is that while they may not report to the agencies, therefore not be factored into your DTI, you need to monitor your debt levels to ensure you're not taking on debt obligations that you're unable to afford.

Typically you can find these trades by driving neighborhoods and taking note of the homes being renovated get out and talk to the crew to find the person who is running the job.  

I dropped where ever I was doing in my office and started to drive for bucks. 

When you factor everything else in, it could be a deal that's not as good as you had originally thought.  

Since it was your initial plan I am assuming it is within reasonable driving distance to work.