I'm going to disclose to the buyer regarding a lien issue which might affect and delay the closing. Should this be done officially via T64? Can I instead notify the buyers agent via email and skip T64?

Full disclosure, I worked for Watchfire Signs in the past, but I no longer do.Watchfiresigns.com would be a good place to check for case studies, although I don't recall finding a lot of good economic data.

(The HOA was fine but the HOA was suing the builder over picayune "defects").These are disclosure items.

Whole life policy illustrations are filled with smoke and mirrors as evidenced by 7-10 pages of disclosures meant to explain the misleading illustration.Return of principal during retirement years in terms of cash flow is “ return of” your money not “ return on” your money.

The buyer asked me to fill out a disclosure.

And DAPT, though weakened, does have benefits, such as reasonable costs and less IRS reporting disclosures.

Kind of like this example I did.https://www.biggerpockets.com/forums/311/topics/780022-3-ways-to-wealth-in-real-estate-cashflow-flip-hold-here-s-howCaution: I mean ummm, Disclosure: I sell Turnkey's In Phoenix, Glendale, Mesa, Scottsdale to CA Investors 

Texas is a non-disclosure state, which means the sales price is not public record.

I know there are plenty of cases where they have no knowledge of the property, but in some cases such as this, I don't think they should get away with selling it as-is without disclosures. 

We actually use a checklist in the application process which provides the applicant to come forth with all sorts of disclosure that can assist us in making a correct fit.