What troubles will come after construction and attempting to sell? 

Regardless, best of luck in this new endeavor!

I know of two groups that I believe could help you in this endeavor.

Yes, they can dispute the charge and then the CC company will have to open a dispute that you will have to answer to attempt to get your money. 

Not the clean report I was hoping for.The numerous remediation attempts and testing have wiped out my profit on this flip.

Quote from @Amanda Henry: We are attempting to collect a $572,379.35 judgment against Chau Ong for investment fraud in Texas. 

If the numbers make sense, the plan is to approach the seller and attempt to get a lower price for this "2-story" building which has vacancies, since that's what the owner is selling.

Not just you throwing bleach on it and painting over it.In general it sounds like you were notified of the issue, attempted to correct the problem but were unable to due to the tenants non response.

Thank you and to you as well with your future endeavors. 

Quote from @Gregory Wilson: A few things there, Brendan.First, an LLC with you as a member and your (wife, son, pal, etc.) partner as a 1% member will file a Form 1065 which is about one tenth as likely to be audited by the IRS as a Form 1040 with a Schedule E rental activity (which I presume you will attempt to show is an active business).Second, you want an LLC because when your local Alabama handyman drives his girlfriend's uninsured truck into a van load of U of A medical school interns on I-22 when he goes  to get some shingles for your roof, on your business, you don't lose everything you have or ever will have to an uninsured claim.