I have a few options.

They can communicate issues to you and source contractors to fix it. 

They say they will sign my lease and also sent me an addendum to sign allowing them to sublet.There are a few reasons why i like this option for this property, but im wondering how to background check the company and the individual they are assigning to ensure ill be paid monthly as they claim. 

There are no perfect options.  

Which option is the best route business-wise is a complex decision.

I've heard of "blanket mortgages" which I thought might be a better option for me so I could use the equity in both properties and only need to get one mortgage.

Good option for getting money for further investing?

I think other options can get you places much faster. 

Call your banks and ask them if they offer any options and try to work with them.Another option is to sell one of your property, consolidate and move on...

The other two options require spending money that is basically going out the door to lots of fees and expenses of exiting your current house and getting into a new one.If you were just looking to move, that is perhaps a different story… If your house isn’t working for you, for instance.