Can silence...

[Sandrone]

...stop rogues from using attacks that need energy or stop warriors from using attacks that need rage or stop hunters from using their special attacks that need mana?

I'm just wondering because I'm not sure what a spell is in WOW terms and I'm not sure if silence can stop the things mentioned above.

[Aerath]

Nope.

Those are not spells. Hunter's specials I am not 100% sure about. Warriors can't use their shouts when silenced.

Similarly, druid shapeshifting does not count either, even though it costs mana.

[Grakmarr]

As far as Hunters are concerned: Being silenced will stop them from laying traps or using Scare Beast, but it won't stop them from using any of their various special shots/melee attacks.

And as Aerath said - for Warriors it'll stop their shouts, but that's about it.

[ZaxGreia]

Basically, if it's a spell, silence stops it. However, it's not a hard and fast rule - it's just another game mechanic Blizzard uses to tune the balance between classes. Sometimes it feels a bit contrived, but it's effective.

Incidentally, it's one of the reasons that warriors do pretty well against casters (combined with spell reflect in Arms spec). Can be quite dangerous in the right hands ;)