Firstly - that is in HotU and not in SoU
Secondly.
The Meduasa is aggresive towards you when you enter.
When you then get the potion that protects against her gaze she turns neutral and you can then talk to her.
It dosen't matter much anyways as long as you get the shard

As for her not using her Gaze when people/henchmen attacks the medusa, well that is poor design in my oppinion, but maybe the battle went so fast that she didn't have time to use it?
Thirdly - the Fool is not located in the temple, but in the castle together with all the Driders.
The temple is located futher to the south, where the "poisoned" quest takes place. When standing outside at the entrance to the castle, just head south down the path and you'll get to the Temple.
I hope this clears up some of the problems, otherwise - just post back
