Hi Javi Navarrete,
I would like to answer your questions in a convenient way:
1. Repeating event occurances are treated as date occurrences of the event instead of being separate events. Each occurrence has a unique date that the event repeats on. An occurrence can be modified. When modified it is treated as an exception of the repeating Event, that is why in the context menu the ‘Delete’ option is displayed too.
More info about this you can find in the API docs of the Scheduler component: https://www.htmlelements.com/docs/scheduler-events/
2. For this I have created a code snippet which will enable you to have this type of functionality:

window.onload= function () {
    const scheduler = document.getElementById('scheduler');
    scheduler.addEventListener('editDialogOpening', (event) => {
        const eventDetails = event.detail;
        if (eventDetails.type === 'confirm') {
            setTimeout(() => {
                const dialogButtons= eventDetails.target.querySelectorAll('.smart-scheduler-window-button');
                for( let i= 0; i < dialogButtons.length; i++ ) {
                    dialogButtons[i].addEventListener('click', () => {
                        console.log('dialog button clicked');
            }, 100);

Let me know if that works for you!
Please, do not hesitate to contact us if you have any additional questions.
Best regards,
Yavor Dashev
Smart UI Team