Its essentially in the longterm best interest of the property owner to ensure there is a non-compete clause in all leases; merely for the benefit of securing longterm relationships with the tenants.A diverse tenant mix can attract a wider audience and contribute to a more vibrant environment.

While I'm not entirely discouraged, I feel like I've invested significant resources (LLC, website, domain) without securing a deal that generates cash flow.Any advice or guidance would be greatly appreciated. 

Zelle is too easy to dispute and not secure enough.

Do nothing...the tenant isn't renting that area and has no right to dictate how you use it as long as it poses no security/safety risk to them. 

That's not really a full story so it's hard to say, but generally, if you don't feel secure or confident in the person you hired, you shouldn't have hired them.

Sometimes it’s the smartest move to gain liquidity and to secure your position with your remaining properties.

This should be signed infront of an attorney.A basketball player had his soon to be wife finally sign the prenup on the day of the wedding....

Visa and FinancingYou're correct that securing a mortgage might be challenging without legal status or a W2 job.

Building out my portfolio with strategic, secure passively cash-flowing assets to continue to build leveraged equity.

You may or may not wish to fix it since its likely too late to charge the last tenant's security deposit for it and also that it sounds so minor that people didn't even notice it right away.