After you got the battle tower did you had back outside on Sentinel Island? There is a dragon skill book you can find in a nest in a tree, some random loot, and the treasure in the boat in the tree that somebody wanted (though you may want to use that item yourself, rather than complete the quest).
The quest in the ministry in Aleroth will probably have to wait until you are a higher level, but you can talk to Zandalor and just tell him you need time to get ready (you can mindread him, as well).
Actually, the opponents in the ministry (once you start the quest) keep spawning until Zandalor is able to close the rifts, and he has to restart if he gets attacked. Some people have deliberately failed to protect him in order to use that location to level. Save before trying that, though, since once you start you can not leave the ministry until Zandalor finishes.
