If they don't, consider involving an attorney.

And this really bothers me because I thought I could be the one to make my family wealthy, but my parents can't seem to see eye-to-eye with me and they'll distrust me even further. 

Since there’s no recorded lien and they weren’t involved during the foreclosure, it sounds like they’re pushing boundaries by attempting to enforce something without proper documentation.

I’d love to have real estate provide some financial freedom/flexibility and create a portfolio that I could eventually get my kids involved with and pass down to them, but I end up feeling frozen/stuck based on the factors above. 

The BRRRR strategy and tax lien investing are both great approaches, especially when you’re getting started and want to maximize your investments.I’m involved in the investment real estate space as well, primarily focusing on new construction duplexes in downtown Indianapolis.

@Zach RumfieldEstimating an ARV involves using public sales data, subscription services, local tax assessor's website, real estate agents, CMA tools, and local appraisers.

Meanwhile our local properties were having increased cash flow without the effort involved with 2 hurricanes. 

When I acquired my own portfolio I did so largely by my own version of BRRR which involved paying cash for a property, fixing it up, renting it out and then a year later getting a Wells Fargo HELOC on them and using that money to buy another house.

I don't know how IL laws are but I think in most places a local municipality can only charge a fee to provide a service and the cost of the fee must roughly correspond to the work involved in providing the service.

I've fortunately never had to evict in Alexandria city - but it is eye opening to read about the city's attempts to keep a non-paying tenant in your property.