how-to 1) remove a key, 2) avoid spam, 3) add a principal UID when delete ?

[Robert J. Hansen]

John W. Moore III wrote:
> If You're certain the Key has _not_ been disseminated anywhere & there
> is nothing encrypted to it that You may wish to recover if/when the
> passphrase is 'remembered' then just delete it.

I think the OP was looking for "gpg --delete-key" and "gpg
--delete-private-key".

> This is much debated.  I belong to the camp that believes having the
> Email Address within the Key UID makes no difference.

Agreed.

> Create the UID You want on the Key and then set it as Primary.  Go to
> the UID You're unhappy with and revoke it.  If the Key has never been
> published to any Keyserver then You can simply delete the revoked UID.
> If it has then re-publish the Key with revoked UID to the Servers.

Might also be worth mentioning that the idea of "primary UID" is kind of
poorly defined.  No OpenPGP application (that I know of) does anything
special with them.  All it affects is which UID GnuPG and PGP will
display first.  Nothing more.