Could I also say: "Я не чув о цих подіях"?
Not in the modern standard Ukrainian.
This is the form used in Russian, so that's why you can hear sometimes it in colloquial speech influenced by Russian ('surzhyk'), but definitely not in modern Standard Ukrainian.
In the past, it was used this way. The dictionary lists this meaning (see point 4) as 'dated' (заст.). But if you use it nowadays, I don't think it'll come off as an old-fashioned word. I think it'll come off as a Russian word (i.e. it would sound overly colloquial).
In standard Ukrainian, «о» is used for telling time:
- Я при́йду о пʼя́тій годи́ні. 'I'll come at five o'clock.'