Then all the number breakdowns were based on 10% down payment using 2nd home loans.

The $75,000 would make a 20% down payment on a $350,000 property. $225,000 would make a down payment on a $1,000,000 property.

Negotiated $198,000 in seller financing through a Promissory Note, pulled a $99,000 commercial loan with a 5 year balloon, and contributed $33,000 as a down payment.

However, is it normal for the property manager to deposit the rent payments into his account before depositing them into my account?

We reduced price as well.The units are still empty and I'm starting to get really tight with mortgage payments and rent (I live in NYC).

With a rate for a first mortgage today in the 6-7% range something like this probably is going to be close to or in the double digits. 

What would the difference be in your payments from 6.7 to 5.2?

My hesitation is that after accounting for all of the items you are supposed to account for when analyzing a deal, the CoC return on the down payment is pretty much negligible initially.

Another approach could be to use LPMI, which rolls PMI into a slightly higher interest rate, potentially saving you monthly PMI payments.

You can put a little as 5% down payment for conventional or 3.5% for FHA.Alternative way, is to acquire the 2nd property as an investment property with conventional, while putting 15%-25% down payment.