Also you should also want to make sure a third party believes you can afford the homeAs an investor myself we are kicking our chops right now at all these “creative finance” deals that borrowers could not get traditional financing on and got some sort of seller financing and they clearly could not afford the home so come end of 2024-2025 we will see all of these defaulted loans on this which I will look to swoop in and buy at 50 cents on the dollar

You loan would need to be ok with this. 

MUCH easier cash management and can leverage conforming loans (remember, legal entities such as LLC's are NOT eligible for conforming residentials loans, so no complaining about having to use commercial lending). 

This is a very advanced technique and if your financial company allows this make sure you speak to them about the risk of your holdings/loan being called if you go this route.Also, keep in mind that if that 2nd loan is paid by your savings account, your checking account, a HELOC, another loan...it still means you are net negative on that property. 

I have been speaking a lot with PMLs, specifically the one's that offer 100% financing LTV and LTCMy concern is that they keep asking me for a loan origination cost, which seems like a scam to meFor instance, one offered 100% financing and then once I completed the application, she asked for about $3500 for the loan origination fee.

If free and clear should also consider a DSCR loan 30 year fixed no income no doc 

It would be using hard money for 1-3 months and refinancing into a conventional / FHA loan.

or should I ask for a 600k loan and lay out my plan to my mortgage  broker?

If you come back here and say, you called every lender on biggerpockets and sat in the chair of every local bank in your town and no one had any idea how you can get a loan, we can tell you what to do next. 

Sounds like you are referring to a non-recourse loan, like a Fannie Mae or Freddie Mac Small Balance Loan.