Limitations of Categories when used as distribution list

[ellenq]

When using a Category (as opposed to a distribution list) to send emails to a
group, you lose the ability to compose first, then add the recipient, which I
usually do to avoid sending an incomplete or error laden email to a group.

Is there a way to add email addresses from a category after the email is
composed without copy/paste?

What about the need to move addresses composing a category from the "To"
field to the "BCC" field without copy/pasting. Any way to do it directly?

Thanks.