I am curious what is a market correct "finders fee" for bringing the company deals we are able to close?

You are correct, that this has long been the conventional figure used to estimate cost for buildable sf in NYC. 

correct and at new rates

SEO optimization with targeted keywords can significantly boost visibility across these platforms.Strong photos and virtual tours tend to convert leads more effectively - tools like Asteroom or Sphere.app let you create these yourself.

But the garage is not included since I need it for storage of my tools and supplies. 

Tools like Rentometer and BiggerPockets can help compare rental prices, and working with a CPA and attorney will ensure you structure your investments properly.

To get started, you’ll need a good understanding of assigning contracts (check your state’s laws), a solid buyer’s list, and marketing tools to connect with motivated sellers.

So a little over 7 months construction period, a little longer than I liked it to be but it's our first time building a house like this so we took it slow and had to correct some issues along the way.

Is that correct? 

Had my inspections done a month or two ago and they checked about a dozen items per property that had to be corrected and told us the properties were deemed "uninhabitable" until then and no one could stay in them.