Enhancements to OA Events

I'm new to OA and Drupal in general, I started to configure a test environment for my organization to be a small collaboration platform.

We have a training activities happening on daily basis. A monthly training calendar is sent to all staff.

I was thinking about having more options in the calendar events to be more like Facebook events that requisites the event notification recipients feedback (attending, maybe, not attending).

So when I create a calendar event, the following features/fields will be available to configure:
- Is the event requires a confirmation from the recipients of the event notification (e.g. attending, not-attending, may be) ?
- Is the event is limited to specific number of attendees ?
- If yes, what is the maximum number of attendees ?

That can be help for planning events, so once I send the notification to all staff, I would know how many is welling to attend to plan accordingly.

Also for training events, If I have a limited seats on my training room, people can see the number of seats for that training session, how many is already reserved and how many is remaining. Accordingly once the training is fully booked, no more registrations will be available to other staff.

Thank you,
Haitham