There certainly is a cost to the broker but a local/regional bank typically has a portfolio allocation limit that may limit what they can offer you no matter how good the property is. 

Typically, the down payment required gets bigger the more units you buy.Lastly, what are the cash reserves required on the property (duplex) I'm departing, and the next property I buy (I'll be aiming for a triplex)?

Is this a typical cost to get started?

Any legit contractor with proper experience, a decent rep,  a gc license and insurances can typically be approved.You absolutely want a Lender with plenty of 203k experience....they may give you a couple of contractor names they have approved, or not.

Are they typically taken out in their own name?

Based on very little information and having to make assumptions such as no additional income beyond rent (Garage rentals, laundry etc), vacancy of 5%, expenses for 30 units buildings are typically between 40-50% depending on class of property and age of building, assuming class C. 

My goal is to create instant equity, get 3-5 years of accelerated debt-paydown and end up with huge equity (or paid off properties)...typically selling or paying off the property at that point.

"How you doing, your family member is selling me the roof over your head and you need to leave" doesn't seem like a good conversation starter.Lastly, is there an industry standard incentive that typically works to motivate "tenants" to move out sooner than later?

Non-occupied conventional loans will typically require 25% down.Again. discuss this with your lender and be honest about your intentions...they may have a work-around. 

In other words, take your time in putting together a good property with good paying tenants to get the best valuation for refi or exit.Most lenders can do 70% - 75% LTV max.Expenses for MF typically range from 30$ to 40% of gross rents.