Mortgage question about lender pull

[Juss11]

My wife & I met with a lender today. Im kinda confused. First my score on here(myfico) are right at 700, wifes about the same. She pulls my scores and my middle is a 655. Way lower than I thought. I know differnet scoring model etc. So I ask her what fico model she pulled? She said they pull strait from the CB. I say I know but what fico model? She has no clue what im talking about? She said she never heard of a different models & I could tell she thought I had no idea what i was talking  about. So she fisgure our DTI and say its like 45%. Im like what? I figured it to under 20%? So were only using my income since my wife has not been at her job long. So my income is 75k and our min credit card paymets are(5 cards) $320 & our two car payments come to $758. So does that sound like 45% dit? We have banked at chase for years anf both have two CC with them. Since she already pulled our credit once it wont effect us to have them pull to see what score they get right? You get  15 days to shop? If we do go with the  lender (one we met with today) will she get notice we are shopping arund? We were pr-aproved for 250k We were hopping to get a little more than that.

Thanks for any advive given.

[Juss11]

Also another thing I didnt understand. she was saying I can get you in like 4.1% & if you need help with closing we can go to like 4.5%. That way if you need help with closing cost you got like 5k you can use for that. BC you took the higher rate, your getting like 5k to use in you need it. She said most banks just keep that money & we dont. Is that like buying points?

[TurboFX]

You are getting a higher rate 4.5% instead of a 4.1% in exchange for $5k lender credit to help offset your closing cost. Buying points is when you pay additional cost example: 1 point (1% of your loan amount) to go from your 4.1% to a 3.87%.

[TurboFX]

Your dti would include your current debts + the estimated payments on the new mortgage. I haven't checked the numbers but seems to be right for a 250k and your income level.

[pizzadude]

It's not unusual at all for some lenders / loan officers to be unaware of the specifics of the FICO scores they use. 

Mortgage lenders almost always pull the FICO04 classic scores, which are not the same scores sold here at MyFICO, so there could be differences, as you noticed.