I only ask because I've seen many investors also get burnt out, switch careers and even liquidate their entire portfolios because of it.

At this point in my career, I'm not looking to purchase more properties, but would like to invest in real estate via tax liens.

Each option has its pros and cons that can impact your investment strategy and overall success.HELOC (Home Equity Line of Credit)Pros:Lower Interest Rates: HELOCs typically offer lower interest rates compared to hard money loans.Flexible Terms: You only pay interest on the amount you draw, providing flexibility in how much you borrow and when.Revolving Credit: As you pay down the principal, the available credit replenishes, allowing you to use it for multiple projects.Longer Repayment Periods: HELOCs often have longer repayment periods, which can make managing payments easier.Cons:Qualification Requirements: HELOCs require good credit and sufficient equity in your primary residence.Secured by Your Home: Your primary residence is collateral, which means a default could risk your home.Variable Interest Rates: HELOCs often have variable rates, which can increase over time.Hard Money LoanPros:Easier Qualification: Hard money lenders focus more on the property’s value and potential rather than your credit score.Speed of Funding: Hard money loans can be approved and funded quickly, which is beneficial in competitive markets.Flexible Use: These loans are designed for real estate investments, making them suitable for purchase and renovation costs.Cons:Higher Interest Rates: Hard money loans typically have higher interest rates and fees compared to HELOCs.Short-Term Loans: They usually come with short repayment terms (often 12-24 months), requiring a quick turnaround on your project.High Fees: Origination fees and other costs can add up, increasing your overall project expenses.For a BRRRR strategy, a HELOC might be the better option if you qualify and have sufficient equity in your primary residence.

So now we have conditioned when a person leverages self to the gill's, taken on mountains of debt and the grand some of there career is waiting tables or making coffee and some toilet-paper degree that a bajillion others also have, and maybe a few years experience at best. 

My wife and I currently make more money than we did in our corporate careers but (legally) have not paid any federal income tax in several years. 

It matters less how many units currently owned, but how many units have been bought, held, and/or sold in one's career is meaningful as one of several measurements a prospective passive investor should use to evaluate a sponsor's experience.In this context, door count is often misused by sponsors who count deals they are invested in as an LP, or deals they raised capital for as a capital raiser where they had no operational control or responsibility. 

Infact, it's advertised online with the Realtor.com site showing all the amenities of my apartment, the electrical, the plumbing, the windows, the door, the shower and toilet and even the kitchen sink so obviously it must be legal because I can't see an agent of his caliper risking his career and livelyhood for undisclosed info.

I am retired and working on career #2 and 2 of 3 of our kids have left for college - our oldest is headed to UConn for her PhD (6 years) and instead of paying to rent, our thoughts are to do a version of a house hack with buying a house/condo and renting out one to two rooms to offset the costs of her rent.

They tend to have a passion for this career and are possibly long term tenants in the area.

It's one of the non-transparent gentrification+migration in history due high COL.For young people and business, it's no longer make sense to live independently in CA even to pursue career so TX gives better choice.