The two methods being utilized are Income Capitalization and Sales Comps.

@Stephan Ketterer the problem you're going to run into there is that the owner of the building is not the one paying the utility bills in most cases, it would be the tenant who may or may not have authorization to make modifications to the building, they also might not stay long enough for the upgrade to pay off. 

I had a hard time wondering if I can utilize the BRRRR method with an FHA loan.

Mostly a GC on several rehabs and renovation projects.Average monthly income on 218 is $25 per door, $5,450 X 12 = $65,400Average projected annual PM income is $465,720With our own properties running smoothly, this number is much higher.EXPENSES (estimated):Monthly office, utilities, insurance, operations is about $1,100/month X 12 = $13,2002 Full-time and 2 part-time employees can manage 200+ with good systems in place. 

Have anyone utilized these particular sources and if so what was your experience like?

Leverage is everything -- if you want to expand, make more cash per month, you have to utilize what you have.

My questions may seem simple but I fully understand its complexity: what is the best way to make this happen, what direction do you recommend for the refi cash out, what strategy to utilize to help guide me on this journey of educating myself and building confidence through working in notes and multifamily acquisition and ownership?

So I looked into converting the whole building commercial and have offices upstairs.And yes, you get more rent and commercial tenants also pays real estate taxes and utilities, they expect it, unlike residential where you get pushback when use ask for them.

As we have been saving up cash of our own to invest in real estate, we came across an opportunity to utilize her moms primary residence to pull a HELOC to invest (possibly 80 - 100k).

Before going down the road, I'd check to see if/when you could utilize any of these losses.