As a result, for the new house I would buy, they want to charge an extra 25% of my current mortgage as a down payment on the new house, in addition to the 20% down....Do you know anything about this?

From our discussions, targeting a 30% occupancy is what most people use for numbers and income predictions.Evolve does a decent job and charges 10%. 

---> Should I charge an application fees or not ?

They will charge 8 to 10% based on property condition and the local market.After you remove all the extra expenses from your balance sheet, this deal might be tenable. 

If I'm reading that correctly, the takeaway is that a delayed financing will top out at 75% LTV, but if I can nail my purchase price and any rehab costs inside of that number, it would be possible to take out the full amount via the delayed financing loan (by including the rehab costs as a Settlement Charge on my Closing Loan Docs)?

Can I sign a contract with property manger through my LLC as and receive income and charge expenses through my LLC?

They set any and all terms within the guidelines set forth by those in charge. 

Make sure to charge a fee for the background check and rental application.

I would rather pay 8%+ upside to an equity investor than whatever a HML would charge.

Property management charged me about 10k for no value added repairs and other mismanagement items.Please provide me tips what I can do if tenant continues to not pay.