There would be nice to have the tree of elements on actual page shown on some panel. This tree could by default flat with all elements:

• Element 1
• Element 2
• Element 3

Another level for groups, when they are grouped:

• Element 1
• Group 1
  • Element 2
  • Element 3

It would be very heplful to access particular elements from this tree (click the tree = focus on the tree and the editor), because sometimes it's very hard to access elements that have gone to the bottom.