I’m torn between selling it and pocketing that equity, invest it in index funds, my Roth IRA, and keeping some in my HYSA, etc.

I would personally just turn each unit over as they come back up for lease, then increase the rents and fix it up over time. 100k is a downpayment on another place and/or reserve funds. 

I plan to sign up for a free trial on this platform: https://urlbox.com/screenshot-api After some reading about this, my idea is to: - check which companies are selling in my area and create a visual database of their listings (Zillow); - use automated screenshots for competitor analysis (locations, prices, open houses nearby); - track SERPs - track my progress in different queries to analyze the success of my campaigns;- possibly create visuals for social media/presentations As we all know, it's one thing to read that something is a good idea and another how it is implemented in practice.

I am also a licensed agent, and I buy all investment properties for my company, I am working for.

Then tell the agent to run comps for ARV based on updates you do.And you also said you can't afford to lose $20-30k, the most seasoned flippers/investors lose money all the time, and ultimately that is part of your education costs, hopefully you don't make any costly mistakes, but you have to run your numbers well enough to make sure there is some 'ooops' fund to help shield you from that.As for comps, typically, appraisers want them to be in the same neighborhood, within 15% same square footage, same # beds/baths and age.

Doesn't work that way.When you start getting into larger buildings that have been run by property management companies historical data becomes more important and a bigger predictor of future performance.

Likely due the the temporary housing company's policies.

You might want to hire a company that specializes in this type of marketing. 

Does the company do leadgen?

If it is in a true vacation market most furniture companies will come deliver and setup.