Hi @BNugent7,
Marketing emails or sales email sends in HubSpot always require a contact record - unless you’re okay with tracking them to the wrong record. In that sense, importing these contacts and creating contact record in HubSpot is the correct way to go - assuming that there is a legal basis for reaching out to these contacts and processing their data.
After the outreach, you could remove disqualified contacts to keep the CRM clean.
If you want to be able to identify event contacts easily, I’d recommend setting up two multiple checkboxes properties, “Events (registered)” and “Events (attended)”. Each would have all of your events as options. After importing, you can use these fields to append the event value and thus better keep track of them.
Best regards!