1 re-reads count
2 1000 posts from each participant would be a bit much . Better to just edit your op every week or so (Or just tally them up at the end of the year).
3 any format counts whether it's digital, physical, audiobook (imagine the fun you could have with onomatopoea), or even Braille
4 each volume is one book, not each weekly instalment (or chapter). omnibus editions and Vizbigs would count as 2-4 comics depending on how many volumes comprise the book.