Contacts in a workflow will stay in it, and the new trigger will add any other contacts that meet the new criteria.

When you pause a workflow, no new contacts will be added to the workflow and contacts already in the workflow won’t flow through it. Everything will pause.

No. For example, if you change the trigger to only new subscribers the ones in the workflow will remain in the workflow and continue through it.

They stay on the last node of the workflow until it is their anniversary or birthday again, then they are moved to the start of the workflow again and move through it.

A contact can enter a workflow with either a mobile number, an email address, or both. If a contact has only a mobile number, they will move through the email nodes, but not receive them, and only get sent the SMS nodes, or vice versa.

They stay on the last node and are marked as completed on the node reports.

Yes you can, and the contacts will move through the new actions as normal. The reports will change to show the contact is in progress.

You can delete nodes that have no contacts sitting on them. If there are queued contacts on a delay node, or on a message node, you cannot delete the node.

The action will only be performed on contacts already in a workflow if the node is added below where the contact is.

If a contact unsubscribes from a workflow, they only get unsubscribed from the message type that they unsubscribed with.