Many Buyers and Buyers agents here are skeptical of the "Joe Schmo" homeowner who "took care of it himself" so as others have suggested, for peace of mind when you sell it I would have a clearance test or air quality test performed by someone so you can show it was remediated correctly and 3rd party test results show that. 

Also the things you did yourself were never performed by any contractor or employee. 

High performance insulation/envelope and drywall HERE WE COME!

Is there usually any up front fees or do they only charge once they perform a service for me? 

Its time to get an attorney on this if nothing else to perform risk management because the deposits are not your money but property of your tenants.

But I would try and make sure you have enough reserves to survive a multi year bad stretch where rents plummet.

Currently hold a corporate job which I plan on getting rid of within the next year thanks to my new career as a Real Estate Investor.Although I’ve just recently started my professional career as a Real Estate Investor, I’ve received extensive professional training from long time experts in the field, successfully closed a couple of deals of my own already; as well as helped Cash Buyers find great deals in my area meeting and exceeding their expectations.My immediate goal is to specialize in wholesaling deals, finding the best deals for my cash buyers per their personal criteria.My short to medium term goal is to buy and hold at least 5 or more rental properties consistently producing the highest cap rate possible with a double digit cash on cash return within the next 5 years.

The plan was to rehab the house to a 5-bedroom, 2-bath home with a main floor master suite (the existing layout did not have a master suite).What was supposed to be a 3-month rehab stretched into a 6 1/2-month rehab.

Martin It would be a really good itdea to have an experienced Architect perform an accessibility review of your property for compliance with accsssibility standards.  

Granted his target audience for this advice is largely those who have trouble managing their finances, but a lot of investors with strong financial management skills might be better off performing their own analysis to arrive at a decision to finance or not.