My old character was blackblitz.  I clicked the link 'accepting new applications', and it said I was dead.  Why does this happen?

If your character was 48+ hours old and unsponsored you will be shot... It's just how things are.

However, if you clicked "Accepting New Members" in the Crew listing page it does not mean you joined that crew.

You have to request an invitation given to you by a Sponsor or a leader/hand. This invitation will appear in your personal news... This is where you accept it.