Depending on financing, it could cash flow anywhere from "meh" to "I can live with that". 

The seller can disappear from contact over time and not be available when you go to sell - you need their assistance oftentimes depending on the lender.12.

It will depend a bit on comps, similar to an appraisal. 

A lot of your STR success will depend on you, your systems, your rules, and your common sense.

-A higher pitch roof has a higher cost and should be considered if your duplex will be infill into an area where there are other homes with the roof pitch, but failing that we have not found that it has a real impact on appraisal (we are in an area of lower pitched homes however so take this with a grain of salt depending on your market) and a lower pitch roof means lower maintenance and capex costs.

It's passive and the initial cost can be flexible depending on your budget.

Ultimately, the choice between vinyl plank flooring and wall paneling will depend on your personal preferences and the overall look you are trying to achieve.

It also depends on loans that you are trying to qualify for depending on credit, experience, and other factors.

Really depends on the route you are taking as to market I'd suggest.

Depending on whether you use a "light-doc" program or a "full-doc" program, rates will change.