At a minimum you’re required to disclose your license in any real estate transaction or proposed transaction you participate in.  

Securities and Exchange Commission in January, the company’s real estate business lost $1.12 million, although the firm had relatively little debt compared with the stated value of its assets.The company also disclosed that it may use new investors’ money to pay dividends to existing ones.

Many states will require disclosure of the ultimate beneficial owner of the LLCs and will not allow a managing member to be a corporate entity without its/their manager members disclosed. 

I think in my area if I required prospective tenants to fill out an application first it would scare off some potentially good tenants who want to make sure you are a real landlord before disclosing all their personal info to you.

I thought if Owner signs the agreement with PM, and give power to sign leases with Tenants etc then the Owner does not need to be disclosed on rental lease where other party is Tenant. 

In cases like this where you have exposed more even more problems within the house, that you will now have to disclose, it is not likely that you will be able to sell it what you paid for it.2.)

Your numbers seem solid, and a DSCR loan is a good fit for this kind of deal since it focuses on the property's income, not your personal DTI.For the down payment, using a private lender, partner, or equity investor is usually more sustainable than a hard money or business loan lenders often frown on borrowed down payments unless properly disclosed and backed by collateral.

If they believe their work was done correctly, even if it was not, then in most areas they are not required to disclose (some jurisdictions have requirements to disclose owner builder work).If the work was done by a licensed contractor, which I suspect it was not, then you likely have more recourse.I suspect the work was done owner builder and the owner believed the work was done correctly.  

Quote from @Charlie MacPherson: One issue I see is the "relationship disclosure" or whatever for of that your state requires.Here in Maine, the agent is required to present a form disclosing the relationship to the buyer upon the first meeting to discuss real estate. 

But they set up their business so that the chances of being sued are minimal; investor expectations are realistic; investors (and be sure, in your scenario the seller is an INVESTOR in your deal, if you don’t think so look up the SEC definition of investor) are informed of ALL the risks they may be incurring, and the business model includes disclosure documents that disclose EVERYTHING that may be relevant about the sponsor, deal, etc.