Both of those things would really drive me mad.
I can't bear the sound of people eating. Or excessive crackling of packaging eg when eating crisps or sweets. I think 'just eat the f##king things and stop making noise with the packaging'. It's especially annoying when at a show, deadly silence at a really tense moment and next thing CRACKLE CRACKLE as they rummage at their sweets.
I was at an event yesterday where we were standing listening to a speaker. The person next to me took regular long LOUD slurps at her mug of coffee. I couldn't move without distracting from the speaker so I had to grin and bear it.
Aaaaaaaaaaaaaargh.