I figured its a win win, they get to invest into some real-estate and grow their retirement as well as it will lighten my investment and potentially allow me to get into a better property that would cash flow/appreciate better.Does anyone have personal experiences or opinions on this?

I would say if you can do it without a friend, that is a much better situation. 

If so, you'll get better terms, although not ALL lenders require US scores.

Even if you do nothing with it, at least you have it and the sooner you act the better.  

Salem, for example, often offers better cash flow opportunities compared to Portland.

They don't say it's the animal they make an excuse like "better candidate" when you were about to sign until they find out you have a animal.

More institutional lenders are getting involved in the hard money space and much easier and better to work with as there is structure to the process 

Is it better to create a new EIN or is it better to create a TIN or just use my personal SSN?

.- Another thought to give why would you want to do a rental at all, I mean those terms are horrible. why not buy something else with a better return on invest?

But you will sleep better.