One last question. What's going to net me a better deal: having less DTI or having a bigger down payment?
DTI doesn't effect your "deal".... it doesn't effect your interest rate or anything like that... your DTI percentage is either "pass" or "fail". So the fact that you are already approved (or pre-approved) means your DTI is acceptable, so you don't have to think about that anymore.
So only pay down your credit cards/medical bills if you want to get rid of the high interest payments quicker (but if you spend your money on debts, then you'll have less for down payment/closing costs).
DO YOU PLAN TO RETIRE IN THIS HOUSE?
If your answer is yes: Then it would be worth paying a few thousand in "Points" at closing in order to get your rate slightly lowered. This will enable you to save the most interest over the life of the loan (tens of thousands). BUT THIS IS ONLY ADVANTAGEOUS IF YOU PLAN TO STAY THERE FOREVER (or at LEAST 10 years+).
If your answer is no: Don't pay Points to "buy-down" your rate. It's not worth spending a couple extra grand at closing just to lower your payment $40/mo, if you're not going to stay there long enough to recoup the Points spent AND spend enough years past that to benefit and "save".
Here's what I did with my first house...
I KNEW I wasn't going to retire in the house... it was a 5-year house in my mind...
So I gave myself and INTEREST ONLY loan with an adjustable rate!
When I bought my house, my mortgage loan was for $130,000... my payment was $550 and that was INTEREST ONLY... so 5 years later I still owed $130,000. But I sold for $180,000 so I didn't care too much about paying down the balance because EVEN IF I would have taken a "regular" mortgage loan that had a payment of $720 (principal AND interest), 5 years later I would have owed $120,000 or so...... so when I sold it I STILL would have sold it for $180,000 (that's inevitable) so IT WOULD ALL WORKOUT TO BE THE SAME IN THE END.
So my thought was, why commit myself to having a payment of $720 when I could have a payment of $550. When in the end, it all calculates to be the same.
Here's the kicker with my loan described above...... Even though it was an adjustable rate mortgage, I still got a 3-year fixed period.... so my rate didn't change at all for the first 3 years (payment at $550). BUT once the adjustable period came, my rate WENT DOWN, so my payment dropped to $275!!! THAT was "fixed" for 12 months, at which point it would "adjust" again based on Prime and the Libor Index, which didn't change... so my payment remained at $275 for another 12 months. Then ANOTHER!!
So the loan program you choose... and the amount of Points you pay.... are all depending on your lifetime plans for the home. If you're going to stay there forever, pay Points to lower your rate. If you're not going to stay there for 10+yrs, do some sort of creative financing and benefit from it!