email Campaign VS email Invite to Event

eMail Campaign Module has the ability to track user interaction with an email, e.g.
campaign_log.activity_type = targeted/viewed/blocked/link/send error

the event Module has the capability to send emails requesting a response:
$fp_events_link_declined and $fp_events_link

which triggers
fp_events_prospects_1_c.accept_status = No Response/Accepted/Declined/

What I would like to know is if the eMails sent through the Events Module has been viewed/blocked/send error
I have no way to know if a user has interacted with email or if it has been successfully delivered

Is this assumption true?

In this case an event can not be run as a campaign, because the only feedback I get from invite/eMails sent is Accepted or Declined

I think my only option is to extend the Campaign module, add a custom field to the

or add an extra option to the field

after viewed a person I will embed a link in the email that will allow someone to respond to a question e.g. “RSVP Now”-button triggers custom code that adds a new row to campaign_log using the “identifier” - parameter.