2. How do I see who responded to my campaign(s)?

You can have a related list of Incoming SMS and SMS History object on the campaign module where the responses get attached and you can view the same on the respective campaign

Important Announcement!

URGENT! Please register the 10-digit business phone number (e.g. 555-555-5555) that your organization uses to send texts to consumers in the U.S. Failure to register may cause heavy penalties and disruption to all your text messaging communications.