When importing contact info, you need to enable the auto-enter option during import so that your newly imported contacts get the necessary ID number. This thread discusses this in terms of the Contact Manager, but the issue and it's solutions are basically the same:
I don't think there's any way to add all contacts to a group unless you added that capability yourself. (I'm not sufficiently familiar with that part of the starter solution to give a more detailed answer here.)
I have reimported while choosing that setting and still I can't add the contacts to the list. Now the window in which you select contacts doesn't even open when I click "Add Contact" in the recipient panel. I removed the two contacts I added manually and I think this is why it isn't opening - as far as it's concerned there aren't any contacts.
I can view a list of all of the contacts and search them in the contacts panel, however for some reason I can't add them to the campaign.
Can you confirm that the re-imported contacts have the required unique ID numbers? You may need to identify that field and then temporarily add it to a layout so that you can see if this field is empty or has a value.
What modification did you need to make to the Send Campaign Script to make it send HTML emails?