The contractor's sole responsibility is ensuring the house is rehabbed on time and within budget.

A team that consists of Property Manager, Title Co, Attorney(some states), Contractor, Wholesaler(s), Agents & Lender(most important)  Go in and get pre-qualified for a mortgage which will tell you where you can look and what your budget will be.  

Place needs gut reno so it has been painfully slow working through the pre-existing city violations, getting an architect and now trying to find contractors in my budget for the interior.

I need to add these costs to my budget 

Your reno budget alone is 3x your projected profit.  

That should probably your Maintenance budget not CAPEX. 

If so, anticipate a much higher than usual R&M budget until you get caught up.Also - what's the status of the current tenant population?

I mail to both, but if you're on a budget start with just absentee. 

I currently work as a budget analyst, and I’m very interested in real estate investing.

Plumbing, electrical and HVAC all need completely replaced...this part we had a good idea of, but the excess costs including the mold are escalating beyond what we budgeted for since this is a 3,000 sf house.