First two questions are related to the Berserker subclass of the Barbarian class. I am trying to make sense of it.

1. Frenzy description says “your Rage turns into a frenzy as you release your unquenchable fury and bloodlust”. What is Rage exactly? Looks like I can cast the ability at any point in combat so I think Rage might be irrelevant but I wanted to make sure anyway.

2. I would like to throw stuff as Berserker for damage but I am not sure what are some good things to chuck that I can pick up. Any suggestions for this? So far I have only thrown a mind flayer corpse but the range on that was not good.

The third question is about long rests.

3. Is there any downside to long rests? I was thinking we will turn into mind flayers if we take too long but I am not sure if that is the case.

Thanks.