What do I do if my wife has no credit?
Yes. You can also use her income and no credit score with FHA.

Are private lender mortgage rates different than the banks rates
Sure. The average rate for a private mortgage is over double the rate you find in retail lending.

What's the minimum credit score for a jumbo loan for first time buyer in the Houston TX area?
Most Lenders are different on Jumbo Loan programs as each lender can set their own perimeters for this type of lending. Even though brokers typically have more options in conventional financing, they are usually more limited in this arena than a direct lender. Direct lending will have looser...

What private information is necessary we give to a lender in order to refinance?
All assets in an application needs to be your own money and sourced. All pages of a statement shows the deposits and where the money came from. This validates your money as yours and not borrowed. This is required for all conventional financing. You do have the option to not provide them if you are not using...