Both properties have a substantial amount of equity that’s essentially sitting idle.Would it be a good idea to tap into this equity (through a HELOC, cash-out refinance, etc.) to fund future fix-and-flip projects or purchase additional rental properties?

You point out specifically "... on forum run by his publisher." 

.)- Crime stats... if you know specific zip codes/submarkets that you'd like to target, the best data will come from local precincts. - and more..I'd recommend remaining active not only here on BiggerPockets, but in other valuable RE investment networks that you can find - i.e. local meetups (meetup.com, eventbrite, BP local events). 

I wish there was a system for searching for STR specific things but I have only found something like AirDNA to be the closest even though it's far from ideal for that.

I have never built anything, only purchased already built properties and I need some advice.Thanks!

Where are you looking to purchase in?

However, he asked me to sign a one-year Exclusive Right to Represent agreement, as presented to him by his brokerage.His interpretation is that it applies only when he materially assists me, but I think the boilerplate brokerage language he was given reads much more broadly:"If during the term of this Agreement Buyer enters into a contract for the purchase of Property through the services or efforts of the Broker or Buyer’s Brokerage Firm, or by or through any other persons during the term of this Agreement" (emphasis mine).My concern is that, under my interpretation, if a fellow real estate investor wants to unload a property or if I get pointed to an opportunity by a former agent, colleague, or friend, this agreement could create an obstacle to moving forward with the deal.In the end, I didn’t sign.

I want to preface this by saying I'm an absolute newbie when it comes to real estate investing, but the more books and resources I consume, the more I find myself gravitating towards commercial real estate, specifically hotels!

Purchase price: $45,000 Cash invested: $45,000 Single family buy & holdHey @Malcolm Grundy!

In the Bigger Pockets free book, "Real Estate Rewind", as one of the 11 co-authors I wrote about one such Tax Sale purchase and made money but not enough money to warrant the risk involved.