This Comic's Cast:

Remember, these are stories about the Bunny. At some point the Bunny has to do something interesting. Otherwise it wouldn't really be his story.

Personally, I'd keep all three of those items. You never know when they might come in handy. Certainly the Mega Elixir will be useful if they go up against Lavos.
 
    

When evil spreads across the land, and darkness rises and the monsters roam. When the creatures of the night make beautiful music, and the things that go bump in the night go bump with greater enthusiasm. When the world is in peril and is in need of a hero...

These guys are, sadly, the best the world can hope for. These are the adventures of the heroes of CVRPG. They mean well, they try hard, and occasionally they do the impossible...

They actually do something heroic.