Right now, I'm simply looking at a triplex that we'll owner occupy right now.

Sounds like you're on the paid staff.Sounds good, there is a great lack of understanding of reality, business and economic cycles, property management, effects on properties long term.A paper tiger of sorts, let me know how over leveraging works for you 20 years from now. :)

A double close is simply purchasing a property and then quickly turning around and selling that same property.

Often REO listing agents are simply too busy to answer their phone or respond to email and if they do they may simply refer you to another agent to make the offer.Once you have some experience under your belt you may be able to get on an REO Broker's call list and you can hear about and be ready to make offers before some listings even hit the market.I hope that helps.

We simply approached him and he's interested in moving here and renting this property. 

As far as making sure you are not getting ripped off I would simply request that you get a copy of every rental agreement.

In this case, you get to keep all the profit (which will be taxable) and simply make back the payments back to your 401(k).

Title is NOT automatically cleared, the tax lien is simply in first position so you can probably recover your investment when that happens, but the mortgage liens are NOT.

Ultimately, if it's simply a buy-and-hold investment, the area shouldn't matter too much, except that I want the right amount of stable growth coupled with consistent job growth.

If you're simply doing your own deals on the side (buying and selling) without a formal listing in the MLS or a commission involved, you should be able to continue as if you didn't have a license.