Starting Bubbles: 45
Recommended Potions: 3 extra holes in the ceiling, 7 extra Bubbles in the starting cauldron
Points needed for 1, 2, 3 Star:
70 000, 95 000, 120 000
Special bubbles: Doom Skull Bubbles
Leave either the column to the left or the column to the right intact, as that gives you MUCH better chances to burst bubbles between the EVIL Doom Skull Bubbles that dominates the whole level. Once you have drop one cluster of Doom skulls, you will have a much easier job clearing your way to the ceiling though and can let the high column fall into the cauldrons.
Here is a great level video for Eternal Isles #7-2 by Luca from Italy.