IOf you think we dont have massive secret bleeding edge tech projects still active today... i mean all I can say is I can tell you from personal experience as a person who has had top level clearance and worked on many govt projects... yes there are plenty such projects and not one of them is known to the public... obviously i wont say what they are (id wind up in jail)... but I can say such things exist.
Absolutely incorrect. I have had clearance and can tell you it is perfectly legal to mention you have had or have clearance. In fact when looking for work it is usually the first thing a job that needs clearance will ask, if you had or have had clearance.