Given the laws in California, the most likely outcome is to get them out of the unit and charge them for fees associated of replacement.We set the rent just slightly below market given the long term lease agreement, something I terribly regret.

And with Roofstock’s “rent guarantee” program (essentially Roofstock promises payment 90% of rent starting 30 days after close if PM company can’t place a tenant, as well as covering initial leasing fee.).

If I were to rent it, based on comparisons I believe that I could get approx $1600 per month, minus the $1455 ($100 renting fee, and the $1355), I would be making $145 per month.

I would discourage you from buying condos as they’re typically really High in HOA fees which is completely outside your control (major negative) and usually not investor friendly.

This is not be a personal purchase but rather for the company I work for, so we will also have the cost to build and impact fees and such. 

The only thing that comes to mind immediately is "water marks" on the wood hidden behind a wall in the basement which indicate it was previously wet and dried.

The note-writing and mortgage holding for real property is a strategy that only a few Canadians use and even fewer (to my limited knowledge) come out making any reasonable amount of money (net of fees and headaches).  

Are there any hidden costs to being a realtor that I should be considering?

You hire a realtor a flat fee to prepare contract, disclosures making sure all is legal.

Do the math again (make sure to shop around for a bank with lower fees) and see if there is a solution to increases the value of it in a short time, so you can refinance it later after get a new appraisal after  rehabe....No deal is batter than a bad deal which will stress you out and not worthy of the time and $.