1. exceptions? like repeat every 3rd day? <- yes
What do you mean by snooze?
By exceptions he means that if, say you have a meeting regularly scheduled for every Thursday, but the meeting gets cancelled for one week or perhaps it gets moved to Wednesday that week, or a different time.
By snooze he means that an alarm goes off as scheduled, but you hit a snooze button not to cancel the alarm, but to put it off for some period of time -- ie, remind me again in 10 minutes, or in 30 minutes, etc.
BTW, Microsoft Outlook supports both of these features and is a good model to use. To create exceptions, it offers an "Edit this one occurance" as well as an "Edit the series" option.