You also have to realize that even if you are not using the entire heloc limit "Some" underwriters still calculate the Maximum payment into consideration.There are some ways to pull money out of a Heloc and deposit it into a savings/checking account prior to application to satisfy the PITI reserve requirements.

I was under the impression that all payments should go through the title company.This is our first deal so we're still learning the ropes.

My fiancé and I make about 10k a month and the new mortgage payment estimates are between 4-5k.

Need basic service as in payment collection, escrow collection, monthly statements and 1098s at the end of the year.

I have an opportunity to take over mortgage payments from a seller for their remaining mortgage where I would be on title, but not the loan.

And request payment within 10 days to avoid legal ramifications. 

I was thinking out of the down payment (Increase down payment by my fee amount and reduce the purchase price by same amount). 

:)  You will want to do both A and B. you will want to save enough for a down payment and enough in cash reserves for a rainy day fund.

Or is 20% or 25% the lowest possible down payment on an investment loan? 

Obvious first question is: what happens when the tenant stops making those monthly payments?