I took a look at Account Settings in Skinner Mode and realized you are correct -- there is no "My Stuff" notifications section. Since you can't change the style of the notification on Skinner Mode (it's identical to the way it was on DU3 -- just lights up plain yellow), at some point I must have ditched the entire section thinking it was unnecessary.
However, it obviously is necessary because while the notification style can't be changed, you should still be able to choose what types of notification you want to receive.
I've just restored that section to Account Settings in Skinner Mode, so if you look again, you should be able to choose from the following options:
Show "My Stuff" subscription notifications: The "My Stuff" button will notify you whenever someone starts a new discussion in a forum you are subscribed to, or whenever a person you are subscribed to starts a new discussion
Show "My Stuff" reply notifications: The "My Stuff" button will notify you whenever someone replies to one of your posts
Show "My Stuff" mail notifications: The "My Stuff" button will notify you whenever someone sends you a DU Mail message
If you set the first option to "No" then the My Stuff button will not light up when there's a new post in a forum you're subscribed to. The Subscriptions button inside the My Stuff menu will still light solid yellow, but the My Stuff button won't.
As for providing a direct link to your Posts page without going through the My Stuff menu -- I was previously of the opinion that there wasn't any room for it in the site navigation, but putting something in the left column box, where your username is, is not a bad idea... Let me have a think about it.