Hard money beginning a great tool simply depends on the property you are flipping and the lender you use.

Buyers and sellers should consider some amount of closing money be held in escrow after closing to cover potential problems with the non-responding tenants.Does anybody have any experiences to share with successful use of a Tenant Estoppel Letter, or times they wish they'd know about this tool before entering a Purchase and Sale Agreement?

I've watched several "Webinars" (pretty sure they're just hyped up YouTube videos and not what I would consider a webinar) right here from BP that are really just a push to become a "PRO" and gain access to all the tools.

Be sure to check out the free tools BP provides to help analyze deals you may have and also market insights.

The precise property forecast can vary depending on a lot of factors but the general demand is really what you should use the tool for to make your plans. 

Has anyone used the DIY tool, and are there risks?

They make a trim removal tool that is a like saverDoors can be weird and no house is square and plumb 

Consider starting small with house hacking a duplex or triplex, and use tools like the BiggerPockets Rental Property Calculator to analyze deals.Good luck!

I've had a long career in community development and have a lot of bank contacts that would likely be interested in investing, but I'd need to prove the concept first with an initial fund (there are also a lot of other community development tools that could be leveraged to maximize and scale this).

BP has various tools to help you analyze your deals (rentals, flips, wholesale, etc). : https://www.biggerpockets.com/investment-calculators7.