I also know a few good procurement specialists here that might be able to help answer some of your importing questions and ideas.

Find a persons personality type (Dove, an Eagle, an Owl or a Parrot) and use it to build your strategy.

I will parrot the majority opinion and state that 5 million in 5 years is highly unlikely, but so what?  

@Brooks Rembert I understand, what do you think is our best option in terms of procuring deals right now?

You need to look at that agreement because if the brokerages was (procuring cause- made the introduction or in others ways started the process) they can claim you owe them the money.I wouldn't be stepping over dollars to save pennies.Typically the brokerage might negotiate the LOI but the commercial attorneys do the full lease.

Have you already procured a loan and ready to close?

However the listing agent can for sure go back to your rebating agent and file for "Procuring cause".

While she did procure the opportunity, it's important to recognize the capital and risk you're now taking on.

I am currently helping her with that and procuring work while training in as an appraiser. 

Regarding your costs, I would parrot @Bjorn Ahlblad and say that if you don't have experience in the expenses for a similar complex in your market, then your best option is to reach out to multiple property managers that are highly recommended in your area.  50% is the rule of thumb, but expenses can vary wildly between market and product type so its best to have a local professional give you that guidance.Happy to help with some tips to find good PMs if you need them!