Is there an option to sort subscriptions in my controls somehow? I couldn't figure it out - perhaps it's not even possible. As it is now they are sorted based on the sections they come from, which is one hell of a mess. Any way to have those with most recent replies on top of the list?

No.

That sucks big time

I'd like to see a more robust subscription interface, too. But I can live with the current limitations

Yup. When you post a bit, the subscriptions page becomes enormous mess and you have to scroll up and down and look all through the page to find topics with new posts... that's half-useless