Hey @cj,
The Events Calendar in combination with one of the ticketing extensions would enable people to get tickets to an event, as expected – you can make free tickets, if you want the “tickets” to function more as “invitation” confirmations that people don’t have to actually pay for.
However, all the specific items you mention about tying certain functionality and notices to a specific set of “delegates”, including specific integration with URL query strings being tracked from actions in emails you send to those delegates, are mostly things you’d have to customize or build on your own.
So, yes, the things you’re describing are technically possible to build with The Events Calendar and a ticketing extension as a base to build on top of, but would require extensive custom coding.
Please let me know if this information helps, or if you have any other questions or concerns.
— George