If you tap into the reserve then stop saving for the dp and build back up the reserve.

The main house is a 4/2 2500 sq ft that was built in 1900 and needs to be updated before it could be rented it has a newer roof and stays dry but needs new windows plumbing and electrical as well as some foundation work so it’s on the back burner for now.

It can be hit or miss but at a minimum they can be a short term or back up solution...

Having a hard time finding a policy that covers sump/water backup, but I found one at an okay price.

Sounds like you'll be living in one unit, but I'm not sure how that works with other attached units.When I consider a deal as an STR, I always make sure it will work as a standard rental as a backup plan (they often do not, at least in Denver).

They see their equity market related holdings drop with the market, they freak out and sell, then it goes back up without them.

It may be the case that you will not get many (if any) MFR comps in that neighborhood, so as a back-up, look at what the SFRs in that same neighborhood are selling for, just as an additional reference point.

I'd back up and define exactly what a "good deal" is for you.

I've seen baseball managers have better luck arguing balls and strikes with an appraiser than I've had success disputing an appraisal...even with great comps to back up my case.

Your return air has no effect on the burner section of a furnace, every furnace has an induced motor for this.