3. Class balance is a complete joke in every way.
You might want to... "re-evaluate" your total HP and gear layout before venturing into the pvp world. It is a completely different ball game. :)
1. Excluding graphics, is the game play system in any way an upgrade of its older successful predecessor?
Yes, Diablo 3 is way more balanced than Diablo 2. It is also much more diverse when you factor in gear diversity in making builds work.
Watch this D2 video to understand.
2. Tiny arenas are exponentially less fun than and inversely proportional to the experience that comes with open world pvp, and this should be a no-brainer.
I have to agree on this one, nothing beats open world PVP. Who knows, when things get settled down in the later patches we might just get that.
As of the moment, i'd rather have them fix the label of "Monster Power" to a much more user friendly syntax. Many new players don't understand the lingo and get disappointed upon entering the game. It is also a hassle to turn it on manually in the options and ask random people on what it is.