As far as non-10k users are concerned, their comments and answers to questions that get deleted are gone, never to be seen again. Rep lost on downvoting such questions is restored upon recalc. Their own deleted questions evaporate from even their own profiles, along with any rep gained or lost for them.
Do actions involved in the above — posting an answer, submitting a vote, &c. — still count as activity for the purposes of calculating progress towards the enthusiast and fanatic badges, if the posts they're attached to are deleted?