Rates are similar but FHA has a large monthly mortgage insurance premium that does not go away.

If so, use those and then look at 3/2s updated vs outdated to see what type of premium an updated property is typically getting and apply that general premium to the outdated 3/1 comps.

A good RE attorney will have a template on file and will be able to quicly add your manual edits to his form.  

I’m also worried that since lots of higher end developments are taking place in the area this would (in the 5+ year term) become a less desirable rental for people but could fit someone looking to live in the area without the premium, perhaps.

Edit- I do not have personal experience with this, just my two cents.

And if I tell them our criteria and what we're looking for, I'm a bit worried they'll snatch up the lots that I'm looking to buy, try to sell to me for a premium and/or turn around and sell to someone else.

So I own some rentals with traditional loans, leveraged somewhere between 50-75% LTV each. Every so often I toy with the idea of paying one or two off, starting with the higher interest loans. Anyone know if, besides ...

Agreed with the sentiment that comparables are important and you do not want to overinvest since you may not get a premium. 

The higher the deductible the lower your overall premium    but get quotes on all the deductibles you are interested in.

You can save the money on premiums but run the risk of having to pay for everything in case things go wrong.