Good job on the new server a lot of the old bugs fixed. But the increase in bosses is too much. Some of the old bosses were already difficult enough primarily black temple. Adding spells would make it impossible because there aren't enough people to conpensate for the diffuculty. Heres the suggestion:
1: Keep outdoor bosses, gruul's lair, magtherion, karazhan, and serpentshrine cavern easy. No spells simple tank and dps fights.
2. Make Black Temple and mount hyjal bosses have all their spells but reduce their health by about 50% (i say this because usually they are done by 25 people but the most ive seen is 10-13 people in a raid).
3. keep all other regular no tbc instances regular with all spells and health so other challenges can be tackled i.e Molten Core which previously was well completed and challenging.
This way tier 6 and illidan weapons still becomes the prize of all people it just makes it a little easier yet still challenging to get.