There were no true comps and the appraiser gave the permitted ADU no value as a unit or even as livable sq ft. 

When you find the prospective property and you dig your heels into the research do you have a plan? 

Namely timing, cost, and getting permits and such. 

However, I did pass on the information others by reaching out to selling agent about offers and their contact information for third party prospective buyer/s. 

I've dealt with a lot of permitting and zoning issues, which are never fun or go the way you planned. 

I assume I need to apply for a permit but I'm not sure of the alterations that were made (what walls were originally in place or new wall that were built to convert it to single family).

It's been a long time that rents have been rising so I think the prospects of rents falling is a foreign concept, but just like prices, rents go up, and eventually they go down, so you don't want to be in a tough position with a high mortgage payment if that happens.This is all just my personal experience and opinions of course, and I could well be too conservative in all of this, but nonetheless that's my current thinking on the subject (and thanks for the compliment about being a good resource, I'll look forward to your reaching out again in the future :)

There were open permits for the work done but the title company was unable to find the CO.

Real Estate is about volume and motivation points... you can layer motivation data to pin point better prospects.

As a flipper, you will need to know a lot about managing jobs, proper construction techniques, permitting, inspections, building code, etc.