My credit is good, but I'd hate to see it take an unnecessary hit.

You wouldn't have it reassessed (that's for taxes) , you would get an appraisal, and if the property value is high enough to meet the banks criteria for Loan to Value, and your credit meets their standard, you should be able to refinance.

Looking for feedback on: http://www.rex-credit.com/ and  similar Loan Application sites ?  Are there any 3rd-party sites that review / rank such sites ?

per deal to do due diligence.. and IF they fund they say they credit you the 2 to 3k.... some people have gotten funding.. many others have complained on BP that they lost their 3k plus 1 or more 650s and the deals were never good enough in the eyes of DHM to fund them...

Try smaller community banks or credit unions.

I also have almost perfect credit.

They give you up to $5K credit, deliver the whole caboodle and you can have them set it up or do it yourself.

HELOC (Home Equity Line Of Credit).

As far as partnering with him, a partnership on a rental property may be an option if I can bring credit or financing to the table, but I am getting paid to do the layout design, drawings, and material selections for his new construction investments and client remodels, so no opportunity on that end.

It is difficult to be a successful landlord if you can't read people, because credit reports and income verification doesn't tell you anything about how much of a PITA the tenant is going to be or how reasonable they will behave as a human being.