I think that there should be comments/reviews for packs and maybe ratings! It would be really cool for some people to get feedback on their packs! Maybe the review would have to go through someone first, like on IMDB and Google Maps
you can message artists directly and let them know if you like their work
You mean comments on series/sets, not packs.
It would be nice to be have a chat for every set so people can talk to each other about the set and ask for certain cards they want. In progress sets do have a chat, but no one goes there anymore after a set is submitted.