Hello Meavin,

First, the possibility to remove ID from SEF urls was only introduced in Joomla Routing system since version 3.8.0 (and not yet integrated as an option for all Joomla core components).

For now, i don't have checked the possibility to inegrate this new Joomla feature in iCagenda, but it's something i will have a look at later (maybe not before iCagenda 4.0 next year).
(See options for routing in Joomla 3.8, for Article global Options to get some info on Legacy/Modern routing).

About the date in url, this is a needed requirement to allow sharing of the page, and to direct it to the correct date from another website/social network.
I may see for a simplified way in the future such as www.site.com/events/1-event/date-2017-11-24-20-26 ... not yet checked for the best solution for SEO.

So, for now, you will have to use a third party extension managing SEO, and where you could set rules for iCagenda generated URLs, but don't forget to the usage you have of the event details page view!
(by my side, the system for iCagenda should be universal as far as possible to work in all cases, but individual needs are not always the same).

Best regards,
Cyril