I'm sorry you've had all these problems with what should be a happy purchase.
Real estate disclosure laws are generally quite specific. You should get advice from an attorney, but it appears that in PA, § 35.335a. Seller property disclosure statement requires that, at a minimum, seller disclosures must include the following relevant items:
1) Are you aware of any water leakage, accumulation or dampness within the basement or crawl space?
2) Do you know of any repairs or other attempts to control any water or dampness problem in the basement or crawl space?
3) Are you aware of any underground tanks or hazardous substances present on the property (structure or soil), including, but not limited to, asbestos, polychlorinated byphenyls (PCBs), radon, lead paint, urea-formaldehyde foam insulation (UFFI), etc?
Realtor.com shows that your house was originally listed in May 2016 and re-listed twice before selling to you. I would be curious to know whether the re-listing was related to contracts falling through or changes in agent. A broker and/or the buyer must disclose any deficiencies found in previous inspections or contracts in addition to disclosing any deficiencies found at the time of listing.
I'm not clear whether you had a professional home inspection or if you did it yourself?
It's normal for basements to get a little damp and to require a dehumidifier be run during the summer. However, normal dampness doesn't (in my opinion) generally require that a french drain and sump pump be installed. You're describing very excessive and previously uncontrolled water leakage or dampness, and mold that had perhaps reemerged through the paint and had caused a great deal of mold in the ventilation system. What you describe - fresh paint, new carpeting, removal of the dehumidifier during inspection - does suggest that the sellers may have tried to cover up several problems.
Regarding the wood flooring, that will depend on exactly how that information was relayed. If the listing stated "wood flooring under carpeting," then that's likely a slam dunk. If the seller and/or broker told you that there was wood flooring under the carpets, and you relied on that information, ditto. If they said "We think there's wood flooring under all the carpeting," that's a little different and you should have taken steps to check, or required them to do so.
PA law is quite clear about remedies for intentional or fraudulent misrepresentation, if you can prove your case. The buyer can collect anything up to three times the amount of damages from a listing broker that was complicit. The seller may be responsible for repairs or even have to reverse the sale.
I would suggest that you gather up all your proof, pictures, work details, disclosure statements, and the contact info for anyone you know to have worked on the house prior to sale, and head to an attorney if you're not able to come to an agreement with the broker and/or owner. You need to find out when Powell listed the property - if they listed it after the work was done and the seller did not disclose properly, they may not have known anything about the previous condition of the basement. You should also ask the broker to disclose the name of their business insurance agent.
I hope, regardless of what happens with your case, that you and your wife will be happy in your new home, now that remediation is complete.