Don't require 50 reputation for commenting on questions
101219
Allow comments for all users; create comments review queue
138333
Do not allow giving minus one for new user questions
34339
Lower the amount of reputation needed to comment
49487
Why are low-rep users rate-limited when posting questions?
134831
Ability to create questions with vote or comment or both disabled
52100
Allow new users to flag comments on their own posts
134870
Different implementation of downvoting: require comments
99686
Why not make it mandatory to leave a reason/remark upon down voting?
119214
Minimum reputation for answering your own question should be higher than what is needed to ask
84130
If downvoting is so important, why does it cost reputation?
110606
Can we get a comments only lock?
15279
Implement a Selective Comment Ban
56841
Make it more obvious that commenting is only possible after earning certain reputation
128731
How many downvotes do you have to get to be banned from questioning/answering
110470
Why appropriate comment is not compulsory when someone down vote any question or answer?
62952
Prevent questions on Hot List from being upvoted by casual visitors (only rep is from association bonus)
136670
Why do you need 25 reputation on Meta Stack Exchange to use chat?