Right now I would like to change my corporation's address from my Canadian address to a USA address so that I can build USA credit with no attachment to Canada at all.

They promised access to private lenders that lend based on the deal and not someones credit.

Is your question specific to the credit check and/or background check?

I do have a great credit score and debit-income ratio.

Or use a credit card with a set completion date.  

I took it all back as I paid him with credit card.  

I had impeccable credit, but now it's very poor.

No I do not see this as an issue, many have stated that back in the 80s, the credit card interest and auto interest was eliminated and both have growth and seen new heights in their respective businesses.

25% down or 20% down, my credit and income are solid.2.

I'd say that 25% is the prevailing number you should be thinking about but it won't take 5-10 calls to regional banks, credit unions, etc. to figure it out.