If 4, what are you suppose to do with the parent bank account?

But will the bank be okay with that assuming I'll have to finance? 

This depends highly on what area of the country in which you live and what banks are available.

Someone told me they reached out to the bank in advance and it was fine, but how often will that happen?

She still believes all that we were brainwashed with and thinks having all your money in the bank or a mutual fund. 

Another important piece to to buying our home was the mortgage broker (Jeff Shoemaker- Citizens Bank) and he was awesome.

But prices will continue to rise as well so you'll still be making bank.

Unfortunately there are a lot of agents in the biz that just don’t know how to handle transactions that are out of the box (bank financing with standard down).

Well, it’s not “just like cash” but presenting a preapproval that shows it was a Complete process with tax returns, W-2’s and bank accounts reviewed always helps.

Hurricane/La Verkin/Virgin historically have been much more flexible but those ordinances have changed over the years so you have to be careful before banking on being able to do vacation rentals.