Can I change my community’s notifications? (to aggregated by day, or by week, or as soon as a new comment on an community I belong to is posted)

Yes, you can change your notification settings from your personal profile, simply follow the step below:

1) Click on "Account Settings" which is located at the upper right hand corner, under your profile photo.

2) Click on "Notifications".

3) Select how often you want to receive notifications from the Communities.

6) Click on "Save"