I\'m sorry to say this, but those ideas have been thought of, and they\'re already implemented, just not the way you want them to be.
First of all, the arena is for massive all out pvp\'ing, such as 10 random people jumping in and mercilessly slaughtering eachother for no apparent reason.
Players can team up and head into the wilderness where they can find \"teh uber monster\" and slay it. No need for special arena functions just to do that.
And last, but not least, guild wars is what is used to settle trouble beteewen guilds. The arena is not needed for this either.
So generally your ideas are quite good, they have just already been though of, tweaked and implemented in a slightly diffrent way.
