I also own a small agency that helps with front end site development and cofounded an app that has 250 paid customers.I'm looking for any opportunity to solve any major pain points in this space using software.

I would allocate a property blocked for owner used more on the percentage of blocked time and how demanding that property/owner is during that time.

The other thing I'd add is you have a better chance of finding a deal, assessing and mitigating risk in a neighborhood you are most familiar with and are in most often ... literally walk around the block where you currently live ...

I rent a similar 3/1 unit for $1200 a couple of blocks away, but there is a townhouse rental complex nearby this unit that rents for 1100 for similar 3/1 units that appears to have brought down the rent either via proximity to that complex. 

I recently purchase my first property to flip:I have run into a road block.  

I read that some appraisers do go about .25 miles from the subject property to produce a comp value, but in the particular neighborhoods I'm talking about there are 3 month or less comps on the same block.

However, I am running into a block because I don't really know how to estimate the rehab cost, am I supposed to view the properties with a contractor or appraiser?

Two blocks from Wooddell.

I am thinking of a couple of options1. just paying the amount (~20$/month) for using the space heater if I need to in any particular month2. sending them legal documents (http://legaldocspro.net/blog/warranty-of-habitability-in-california/, http://www.hcd.ca.gov/codes/state-housing-law/hcc/hcc_ap2.pdf, )3. moving out, and getting another placeMoving out is going to be a pain, so I am thinking of either 1 or 2.

I went through it and I feel your pain.