You can’t develop a rule of thumb unless you want to get burned.

You sound overwhelmingly not ready to do this in my opinion and are ripe to get burned.

Shop around you will find lender who would do HELOC with promotional rates of .99% for the first 9-12 months..

While a lot of cities are promoting higher density, actually getting a home in a residential area rezoned to allow multi-units is a tough road.Something else we do with some clients, and you could try to find yourself, are traditional SFH with multi-unit zoning that have potential for a separate entrance.

The base rate you pay for premiums is paying towards a worst case scenario - total burn, etc.

In other words, there are still lots of unfilled construction jobs that, if filled, would promote a sharper rebound in new construction.

As a landlords we should be reference-checking and doing the proper due diligence so we don't place someone in our asset that has already burned a past landlord.

Out of my 14 tenants, all kept their employment and continued paying rent; what's more several actually secured promotions in essential industries including construction and marijuana.

Your wife is likely also stressed due to her job workload but the silver lining could be because she's working hard (and 75% of her coworkers were let go) once Covid is over/has waned she could and should receive a promotion and a raise. 

We refinanced a couple of months ago and will be moving due to a job promotion.