Learning how to do a BPO's (brokers price opinions) will help you learn how to accurately comp properties.6.) 

Gambling is more fun when you have money to loose don't you agree?

Just remember any sort of historic renovations and maintenance are going to cost you much more than a standard upgrade, so if you're renting this out make sure your repair budget is at least 2x (a somewhat arbitrary estimate, talk to contractors who deal with historical renovations for an accurate ballpark on the multiplier for doing historic work) what you would otherwise budget for a non historic house .

I did start looking at the crime stats on Trulia, but not sure how accurate those info is.

I know submetering is the most accurate.

OR you can have a buyer's agent represent you, use MLS data to get you the most accurate comps, submit your offer for you, negotiate on your behalf, etc...Best of luck to you!

We do offer a "ride it" option, where they can just continue to pay rent, utilities & lawn care while we try to get it re-rented, but there's an element of gambling in there that most people don't want to try; if we get it re-rented immediately, they would come out ahead, but if it takes more than a month they come out behind.

The current owner is looking to retire, so your prediction is accurate. 

Also, it's tough to get accurate info for Cap rates in my market as it is pretty information inefficient.

Does that sound accurate?