If the assignor is unlicensed, he might be practicing unlicensed real estate brokering. 

What are the best practices/services you use to produce leads ?

I don’t get soft; stick to your business practice and move swiftly.To your success!

Disclaimer: While I’m an attorney licensed to practice in PA, I’m not your attorney.

It's good business practice and it's the right thing to do, but I don't know if you can force it.

Since I am too young to legally own a multifamily property myself I am going through LoopNet and running the numbers on different properties to find deals for practice.

Some of them are 'bull-doggers' (steer-wrestling) and watching them practice is amazing....they will just stand there, not on horseback, and take down a large steer just for practice.

@Travis HolmbergMy advice would be to give this strategy a shot in Phoenix would be to do it on a property you already own where it's practically guaranteed you're going to make money (already high cashflow, etc.).

What are some things or practices that I should have in order to be that 5-star contractor?

The disadvantage is that nonresident state filings are a PITA and result in higher CPA fees.Some states require nonresident withholding on state tax on a gain which in theory might satisfy all the tax (perhaps even overpay a bit).The technically correct answer is that you might still be required to file, but the practical answer is that it might not be worth the administrative costs.Ultimately the decision probably comes down to a cost benefit analysis to see if the filing burden and cost justifies the reduction in tax you might owe.