I’ll bring in licensed electricians and plumbers for their sign-offs.

Once your income is stabilized, you can do a refinance to remove your coborrower back off of the conventional loan. 

A smaller paid off portfolio seemed a lot easier to manage so that is the path I was on.. but I've come to the realization if I ever want to accumulate serious wealth I will have to use leverage and scale big. 

I would suggest coming to some investing meet ups and just start talking to others and form a plan based off of that.

I took a couple of weeks off from my former job to really focus and prepare for the exam. 

It can be a lot to absorb during your first month, but I think you are off to a great start! 

Jaron Walling said something that caught my attention, "search for and buy a bad roof, leverage it during the negotiation"....especially of the property has been sitting on the market longer than normal for the current market, a "bad roof" might be a gift from the real estate genie.My point is this: get good at estimating and fixing a bad roof (or any particular problem found with most houses that sit on the market longer) and you'll get comfortable buying/fixing properties that scare off other buyers. 

. --- Who gets all the phone calls and wastes time calming a tenant down because the owner's contractor doesn't show up as scheduled after they took time off from work or a 3 day job takes 3 weeks?

It is not uncommon - main reason we see right now is over inflated original ARVs and now borrowers cannot sell and pay off the lender. 

Ft)For ARV, it is best to have an experienced real estate agent find comps for you to determine a safe number to work off of.