On top of that, you need to decide whether you want value conscious tenants or price-sensitive tenants.

I'm much more sensitive to work being done without proper permits.  

Again, refresh your list every 6 months.Some specialty lists like probate I hit every other month and stop after 6 to 9 months.There are other time-sensitive lists such as expired listings or FSBOs which you may want to hit hard ASAP, like every other week for 6 to 8 weeks  because you know others are hitting those same prospects at that same time...A lot depends on the level of competition and the average value of a deal in your market - might do more or less often depending upon such factors....

I try to stick to non-time-sensitive refinance only in the non-qm space.

Since when are debt instruments traded in a secondary OTC market not rate sensitive?

This ties to what @Ryan Evans said of being hyper sensitive to location, which in up and coming areas is somewhat speculative, thus increasing the risk.

They can be very profitable but are also very fragile and sensitive to economic downturns like 2009 and right now. 

Sharing a house with someone while having kids can be a sensitive issue. 

I certainly had my 6mo of living expenses rainy day fund that I took from, a little bit, and other semi-liquid sources I could use in the worst case, but I played it by ear and was able to take my time with many of the non-time-sensitive renovations.Because you're owner-occupying the property for at least one year, you can spread out many renovations such that it's a more constant trickle of cash required every few months or so.

Lenders don't always require Phase 1 reports but be prepared for a recommendation of a Phase 2 report if there has been any indication of above/below ground fuel storage and/or any other type of environmentally sensitive materials.