Been getting nowhere with zoning laws found online and in the local library for Yonkers (in westchester county) as to whether any permits are needed in order to operate such a business. 

There are so many online hard money lenders.

Apologize if these questions are vague, I am quite new to this.Happy to provide some of the data I have found thus far (though data online is scarce given the size of the town).Thanks!

You can create your own, or there are house flipping spreadsheet templates available online 

I bet they were valid.

The fact its in a landbank tells me that it was taken back for some reason, which tells me its likely not a high commercial demand for development, but I could be wrong.If it is "on the main drag" in this town then I'd think doing a new build home to do a targeted and intentional air bnb would be the best bet. 

https://www.biggerpockets.com/forums/93/topics/67638-where-to-find-wholesale-contracts-online

Look it up online and see how much u actually can buy.

Your best bet is to find one that has flexible membership options, without high spend requirements.

Search for this in a Michigan Public Notice legal newspaper or an online legal notice aggregator site like USALEGALNOTICES and the fount of MI pre FC/FC data will be available to you.