I am definitely open to a 5% conventional for a duplex, I've been thinking in terms of FHA because the requirements are more clear when I Google around than a 5% conventional.

In terms of where to invest, it depends on your goals and location.

I would start calling now to interview them and see what the obligations will be in terms of monthly and annual fees/requirements/mls/association payments etc

How can I create a model without having all the details in terms of operating expenses and the state of the property that come with having a property manager review the books etc. up close?

From the comments I think I have an elementary knowledge in terms of overview of the industry but it would be probably be useful to buy some resources (ordered Joe Fairless's book) to go deeper in understanding deal analyses and raising funds.

It's a boutique so pretty unstructured in terms of brokerage requirement; there are a few agents who just do a couple transactions per year but Dominic, the managing broker is willing to be very hands on if you'd like him to be. 

It worked out well in terms of efficiency of cycling the cash and it still performs well as a rental.Last month I helped a client close a BRRRR deal that cost $85k to purchase, $31k to rehab, and has an appraiser-generated ARV of $145k. 

In terms of another platform or forum - nothing is as big as BP, but local REIA FB groups and the NextDoor app will be your best bets.

In terms of controlling the lease expirations I would focus more on the lease term rather than the lease start date. 

In terms of what properties to start with, it honestly depends on your budget.