You can build all the upside you want into the owner carry loan but at the end of the day it all depends on them being able to perform in the future. 

Some times you can get lucky and the 4% will carry over for a little while, but I've seen too may people analyze with the wrong tax rate and end up cash negative every month.

My carrying costs will be $610/month PITI + utilities. 

How should I approach, prepare and present my deal so a RE fund will carry them in their list of portfolios for their investors? 

Besides carrying a gun, what would be the weapon of choice to have for the coming dog?

And I just worry about carrying around so much debt.

That would be correct if OP's father has made or intends to make an S election for the LLC.Since OP did not specify tax status of the SMLLC, we're left to assume no alternate election was made, and the LLC carries the default tax status: 'Disregarded Entity'.A DRE should not be issuing W-2s or 1099s to its owner as it's effectively dissolved for federal income tax purposes and there's no distinction between the owner and the LLC.

(C) You could find an owner carry situation where you pay the seller and they act as the bank for you, and you have ownership....we’ve done a number of these deals.  

Offered a much lower price for cash and offered higher with a little interest to carry us for 2 and a half years.

Rodents are dangerous, they carry diseases.