While doing this you need to be actively networking.

Going forward, I don't intend on being an active agent buying & selling homes, so my question is, short of giving up my license, is there any option to not pay all the quarterly board dues & broker office fees, E&O, etc., but keep the license in some "reduced" status, so I can still possibly reap the benefits of the real estate professional status for real estate investing.

As the buyer you decide what you want to pay and hope you have a agent that 1- will offer it and 2- will do a good job negotiating it.Bottom line is, assuming your agent is fully engaged and on your team, you make all the decisions.

I want to be an active part of the boots on the ground team until I know that I am working with the right people.

I really enjoyed reading his book: it was engaging and a smooth read. 

As you mentioned, I make sure I have enough umbrella insurance.I also engaged in other businesses, so I also file returns for LLC's, S Corp, and even a C Corp for a while, so another LLC for the rentals would just be another return.

So I would suggest getting in touch with as many active MUF brokers that you can connect with just so you get the off market properties.

One for passive income and one for the active side of things.  

I've talked to a few friends who are actively in the business and I'm very intrigued and I've blazed through the ultimate beginner's guide as well. 

You get a realtor license but you can not perform real estate activities.