Im not a mortgage broker but id be willing to guess that income is just as important (if not more) than your credit score. Who cares what the score is if you cant make monthly payments.

That being said, churning cards actually raised my credit score as my combined credit limit is well over 100k now and debt nonexistent.

I also secured a line of credit for a start up business and received no mention of the 15+ inquiries that show on my report.