I have done it, yes (about a month ago, actually). I could have paid cash, but wanted to leave it available for other opportunities.
Just under a month close-to-close. We closed the purchase May 20, rehabbed, and sold June 19. The first payment on the loan wasn't even due until July 1, so we never made a single mortgage payment.
Though the paying 3-5% versus hard money won't make that much of a difference, if you flip it fast enough. You might save on the loan cost though, depending on the points you have to pay with the HML.
Regarding your "I play to live here" question - no, don't do that, that's mortgage fraud. Finance it conventional, but as an investment loan, not owner occupied. You'll have to put down 20-25% and the interest rate will be about 1% higher, but it's still a good deal.