You can easily look them up on https://nmlsconsumeraccess.org/If they are a commercial lender, you may want to check for google reviews

They can review the restriction and let you know if there’s a straightforward path or if it’s going to be an uphill battle.

First thing is NEVER feel concerned of hurting someone's feelings or ego, your reviewing to employ them, that makes you the boss doesn't it?

Have proof on hand (easy enough to find) online of the missed tax payments and any documentation that supports that he specifically didn't pay his taxes.Probably a simply mistake on his part, but now if he wants to develop on it, he either has to land lease it from you or buy it back.I'm not sure how the whole tax deed thing works, so that would be something you have to figure out between the two of you.

Make sure any lease agreement you use complies with Arizona's landlord-tenant laws, including required disclosures (like bed bug information, for example).If you're unsure, consulting with a local real estate attorney to review the agreement can provide peace of mind and ensure you're fully protected.

Every PM operates differently, and at the end of the day, there is tons of information you can navigate on your own in the beginning stages online, but surely there will be PM's that would be more than happy to assist you on journey. 

I read @Dan Deppen's earlier response on this thread and I think what Scott might be doing is employing RMLOs to originate his loans, loan servicers to collect the payments and attorneys to review his contracts and make sure he is compliant with all the laws and regulations. 

My recommendation would be to get approved as a Landlord, contact the director's office and request that an inspection be completed before a tenant is selected (sometimes they will do this as long as you select a tenant within 14 days - which you want anyways), and have an online application and screening resource in place.  

I have been learning how the process works and there are a lot of resources for how to interview a sponsor and review the deal, but how do you initially access the deals to review?

They were simply the king of online bookstores.