Been a while since I filled out paperwork for a gun purchase but I remembers there being a question about using marijuana, which is illegal both federally and state.
Come July 1 marijuana will be legal at a state level.
See where I'm going with this?
Is that question still going to be on the paperwork?
and NO, I don't plan on becoming a marijuana user, don't want to jeopardize my job. But there will be plenty of Virginians who whos to use it and I'm fine with that, but how will that affect their ability to buy a gun?

Yes it will still be on there. That is a federal Form and the state is the one legalizing it not the federal government. Technically if you use it and its still federally illegal you should mark yes on that box and then you won't be allowed to buy a gun. However the atf is undermanned and as long as you don't smell like it and are not high when your buying it the FFL won't know if your telling the truth. I am not telling you to lie on that form but I would suspect a lot of people are going to.

If.... If.... the "state legalized cannabis" was purchased from the Virginia (future) ABCC distribution centers, and the State kept a record of purchases... and then the State shared that knowledge with the NCIS...

That would mean that the State and federal data centers would have to share info.

Also, any future federal "red flag" laws would fund a bigger collection point of personal data (that inevitably be used against you and hacked by China/NK) would be created, then kept current.

This would only apply to those who adhere to following the law.

21, e
Are you an unlawful user of, or addicted to, marijuana or any depressant, stimulant, narcotic drug, or any other controlled substance? Warning: The use or possession of marijuana remains unlawful under Federal law regardless of whether it has been legalized or decriminalized for medicinal or recreational purposes in the state where you reside,