Let's say I get a motivated seller via drive-for-dollars, do I use a realtor to actually arrange the purchase? 

The important thing here is finding out why they don't want to work with wholesalers, what their motivation is, what their timeframe is, etc..Best of luck to you moving forward!

pointless/costly to refinance over and over like that" (because, conventional non-owner occupied loans can also be low deposit).My premise of "only buy bargains" is largely so that each time you qualify for your next (low deposit) mortgage, your Loan-To-Value Ratio should still remain below 80% (even though you might have borrowed 95% or more for each prior one), because you bought bargains in the first place, and/or have value-added to each property. 

The Seller carried 90% of the purchase price, and we privately funded the remaining 10%.

But if there isn't, I guess it will simply remain a black box.

Even though it's a fake show, the premise is that a motivated seller agrees to sell something NOW for less than the market value they are told it is worth.Real estate can be the same way, some sellers will always accept less cash NOW rather than wait an unknown amount of time to get the highest value.So, a good wholesaler doesn't have to steal equity from a seller, they can just offer a quick close for an under market price.

With that ZBA, all of our normal deposits are swept directly towards our remaining balance, lowering our interest cost.

We estimate having about $100k in equity, $72k remaining mortgage ($375/mo) and an estimated value of $170k+, granted, in this insane market.Comps in our area are renting for $1500+ per month (we’re within walking distance of a university and booming downtown area).I feel like we’re in a great position to convert to a rental and leverage our equity but I’m not sure how to approach the conversion of our current home and acquisition of our next.

This is my main motivation to getting into real estate.

Annoying to re set up payments etc but luckily the guy who helped me get the original loans has remained employed through it all and has helped me navigate awful customer service departments, which just gets worse each time.