If I lend to a project inside a zone, do I get any of the tax treatment?

A loan isn't an investment in a qualified opportunity fund, so it doesn't get you the deferral. The election attaches to an equity interest in the QOF, and a note is a note no matter where the property sits. That's the general mechanism, and you should have your own tax advisor confirm it against your specific gain before your window closes, because the window closing is the thing you can't undo.

So you'd be choosing between a 12% second position piece and a deferral you'd only get by taking equity in the fund. Different products entirely, and 12% in second position on 22 townhomes carries its own risk that has nothing to do with tax.

The sponsor's materials saying "OZ benefits to investors" without separating debt from equity is worth pushing on. Either they're marketing loosely or they're planning to sell you equity and quote you a debt rate.

On your second question, if the fund fails a qualification test that's a tax problem for the fund and its equity investors. Your lien and your remedies come from your loan documents and from state law, and foreclosure process differs by state, so that's what actually protects you. What it can do to you indirectly is stress the borrower, because penalties and lost treatment can make equity walk away mid-project. I've managed through a sponsor losing its equity partner and it was ugly at the property level. Ask what happens to your position if construction stops in month 14.