Secondly, i have a 1-3 years of property data that Stessa doesn't see or take into consideration, most importantly rental income and expense. what is the best way to upload that previous data to the properties?

Here are my considerations: Stessa is a great platform for tracking income and expenses for investors, it is really user friendly.

You are close to (or maybe past) your primary residence capital gains exemption, so I'd take that in to consideration too.

So it isn't a complete waste, you would simply need to follow the strict reading of the law with no private clauses for consideration...I'm not sure how that plays out since technically if the lease is void, so is the tenancy meaning you could terminate anytime and not wait for the original lease expiration...I'm sure that's covered somewhere, but again I'd ask my local atty what to do given this is such a locally specific issue. 

Quote from @Will Sherman: Kevin lists some great considerations.

One consideration is that the market we are looking at is pretty hot so properties fly off if the offers are not all cash.

NYC is not even a consideration in any sense.

Real Estate grows your wealth considerably faster when you leverage since the appreciation is on the asset, not the equity. 

Personally I have never been a fan of pre-tax accounts (401Ks and IRAs) because I feel like they constrain my ability to invest in the assets I want, so another consideration you may have is to temporarily stop those investments to save faster for your house.

I’ve been reading about DSCR for a few days now and this has been at the forefront of my considerations for what we’d like to do.