Please share your thoughts:What are some of the most favorable terms you’ve negotiated with private lenders? 

What I would do with the sale proceeds, as pointed out in your post, is reinvest in a first deed private money loan anyway.

Also mother in law suites and private bath are not as available.

What are the biggest challenges you face as a private money borrower?

because I'm thinking no one can really tell you when to sell your property, since it would be difficult to get a loan from a private/hard lender first off.

My second question is for future private money lending.

effectively, you'd either need to look for a lender that would let you use the other property as collateral (cross) so that you can avoid actually taking the cash-out (this is rare in terms of institutional DSCR lenders, but fairly common in the hard money or private money space)...

This would be better answered in a private setting with your tax professional to determine the best steps moving forward and structure.

Any advice for first time buyer on where to find private money and/or a good realtor/property managers in my area of purchase.  

Can we talk more in private message?