To prevent injury, squatters, and theft of any functional appliances or copper pipes, screw plywood over each open window and door.

First it’s something I need to learn anyway so I can generate accurate rehab costs on my projects which will prevent me from getting screwed over by other contractors in the future when I don’t have time to rehab my own houses and secondly I can partner with another investor that has cash and we can split the profits.

That prevents them from just cancelling the check.

I.e. if there were many property losses tied to the carriers property book, the carriers will subsidize the loss leaders with you.I would not advise shopping your insurance every year so as to prevent what we call "market fatigue". 

also what can we do to prevent this next time, our title company closer said next time we should do an escrow agreement, is there anything else i can do to avoid this in the future ?

These guidelines are set-up to prevent fraud.

That should prevent your tenant's tanks from running dry.I believe Devany Oil serves most of the Boston area. 

Learn from your problems to prevent. 

I'm sure you are asking more along the lines of how you could have prevented this or how you can prevent it in the future but it sounds like the handyman messed up when installing the wax ring.

You might want to lean how to perform a title search before spending too much time only to find out he has some baggage preventing him from selling.