Ran into many problems with contractors along the way, paid for some material twice as well as some projects to be redone.

I personally do not have experience managing rentals.

It's always better to check with your brother's CPA since he has all the background, but I would say short-term rental with material participation requirements met by your brother, then do cost segregation.

During 2020 to 2022 I was fighting to keep my business profitable as materials and labor came in short supply and eventually led to the inflation we're seeing now.

This also leads owners to ASSUME simpler is better when it comes to management contracts.

Until then, I'll be trying to absorb everything I can to fine tune my approach and prepare for managing REI business post-acquisition.

Is anyone aware of any of a property management tool that allows PMs to give discounts to tenants who enroll in autopay (similar to how major US phone providers like do these days)?

This is a question for your attorney and accountant on how you will manage the company etc.

Wherever you took your broker's class you should have ample study materials.If you are talking about your real estate agent's license in NJ (that is not a broker's license), you need to take the initial class at an accredited agency and they will give you all of the materials after you finish the 75 hours for the test. 

Popular markets often include beach towns, mountain retreats, and areas with strong tourism.It’s also important to research local regulations, occupancy rates, and management costs to make sure the numbers work.