Question on the Leagues

Is there just an open ended optional pvp world, where you're able to experience everything the game world has to offer without permadeath and disabled regeneration and trade?

I have read the league descriptions and I am having a difficult time with this, Can anyone share some light on this?

I think you can PvP freely in the default league. The other leagues, like Cut-Throat, are just for people who want to play that way, that's why the have special rules.

It wouldn't make sense if you couldn't PvP in the default league seeing as that is where most people are going to be playing.