We will never have the right answer; everything depends on your circumstances.

You should definitely be able to find decent multifamily properties for under $200k, and multifamily would be my suggestion for starting out if you can swing a larger down payment (depending on loan type, you MAY need 10% more for a multifamily vs a single family, but not always).

If you pay retail, you'll be looking at 500k to 550k depending on area and lot. 

some gurus teach this method.. thats all this is.. seller is going to have to pay inputed interest to the IRS though.. to me it would depend on down payment..

These have a much higher CoC ranging from 18-30% depending on how involved you are, the property specific and its execution from a design/amenity standpoint to management.  

A place like this may do ok with displaced parties, but not likely for travel nurses or contract workers based on your description, depending what else is out there. 2 bedroom single-family homes are great rentals because they cost way less to buy and don't rent for much less than a 3-bedroom home.

I work with several investors in the area. and a deal for one will be different depending on what you are looking for.

The best way to estimate expenses is experience and knowledge of your specific asset type and market.For vacancy, that will depend on your market and the quality/desirability of your type of unit.

The home is in a C- to B neighborhood, depending on the person.

But strictly going by the numbers, it's borderline OK, depending on the type of market.