In addition, the investment properties are around the 100K price range. 

Make sure to state in your lease which windows are accessible for AC units (Avoid interior water damage).

I use a database now and can routinely get to within 5% of actual costs on about any reno project...but again, it takes time.One thought is to interview multiple contractors and get bids. 3-5 bids should show you an appropriate range for the work.

I have a shower water line on the exterior wall.

I'm trying to decide on installing a small (24") electric range, vs a countertop stove or induction. 

You have to stay in your FHA probably for about a year, I don't know much about your market but if you went with conventional financing (typically 20%) it may be difficult to find homes in the $50,000 price range. 

For example there are condos in the Henderson area (about 15min from LV strip) that sell for around $220-230k and rent (not fixed up) in the $1200-1300 range. 

And it gives a range and median, so if your unit is particularly remodeled and nice you can use the upper end of that range as an estimate, or if your unit is particularly small or a little rough around the edges you can use the lower end of that range to estimate market rent for that unit.MLS could be useful too because you can view the non-active (presumably rented) listings as opposed to the active ones, but you'll need to network with a licensed agent who has MLS access in that market and have them run those numbers for you.

Such as Target price range of properties, minimum cash flow per unit, Rent to Purchase ratio, minimum CCR, etc.  

That means I will be flying in all types of conditions which is good for getting hired:) Also I really like Idaho for the fact that they offer good fly fishing, white water rafting, and bird hunting.