Mortgage financing advice

[Ari Jiang]

Hi everyone! I'm new to this forum (loving it!!) and this is my first post. I currently have two properties (a multifamily in NYC area and a SFH in RTP area in NC). I have enough cash and DTI ratio to buy more properties, but haven't figured out my strategy (where to buy more, and buy what type) because I'm not super sure how mortgage would work if one has lots of properties.

I’ve heard on personal mortgage, one could theoretically take up to 10 mortgages for properties, but most banks do up to 4. After that one needs to apply for commercial mortgage which requires 25% down and has a higher rate. Is that true? If so would the optimal strategy to use personal mortgage on more expensive properties (since rate is lower and down payment could be less) and save the cheap started SFHs/THs for commercial mortgage? 

Is there a way to get low interest rate once you have lots of properties? 

Thank you in advance!