If you're considering house hacking a multi family property, some lenders might be able to factor in potential rental income to help you qualify.

I can't always be there for my projects, so as I'm trying to implement a system that allows me to always factor in a GC. 

Your accountant should be able to factor that into your total cost. 

Most of the designers I have have sort of a baseline price i.e $2.50/per foot but it can go up or down on other factors

That depends on a lot of personal factors such as your finances.

The cash on cash number is what I liked about it and I think the Capex will not be a big factor because of the Tenants already are there and have been there and want to stay for long term so vacancy was set lower.

While turnkey properties are more commonly used for DSCR loans due to their immediate cash flow, fixer-upper properties can still qualify depending on a few factors. 

Just factor the cost into the rent.

It also matters where the home is located, and what the weather, type of tenants it attracts/has been attracting, etc. other factors are.

But that is calculated after expenses and depreciation is factored in.