Travis, I would not for two reasons, (1) even good dogs scratch up floors, chew on stair corners etc., and (2) if you have kids next door - it may be an issue. 

Usually a puppy is more active and can chew on things more ect.  

However, you can use it to clean the property, replace damaged flooring or chewed trim or whatever.

Or am I way off base here and trying to bite off more than I chew?

If it is constantly more than you are wanting to chew on then now you are just that much better at knowing what a house that needs too much work for your margins looks like. 

I would definitely avoid large dogs that dig up yard, chew up trim, dig up carpet, scratch doors, and can be heard barking from five houses away.

I wouldn't recommend downloading and using a form from the internet because any local lawyer will end up chewing that up the first time something goes wrong.Good Luck!

We have funds to rehab, but don’t want to bite off more than we can chew with deep rooted issues.Specifically been eyeing Chelsea, Quincy, areas of Dorchester, south Boston, and possibly Salem.To make the numbers work, it seems as though duplex is out of the question in the area while turning a live-in profit? 

This is the point where @Paul Sandhu steps in and says, "I give my renters two rolls of Bounty paper towels, a pouch of Levi Garrett Loose Leaf Chewing Tobacco, a bucket of Colonel Sanders finest, and the address to the local strip joint.

Big burly guys that drive jacked up 4x4s, smell like diesel, chew tobacco in their sleep, and have a scorpion tat on their neck.