Shilenne: From the starting zone atm, the roads are more like trails in the forest, which means you can wander around into grass or lake freely. If you stick to the roads there are less chance that you'll aggro mobs, and the trails usually will lead you from one town to another, or to a "save point" where you choose to hearth at or res at after you die. I don't know about the world maps I think most areas are linked, and depending on the area it is the size differ. I would say from how I played so far that one quest won't lead you to the next on the trail, it's more of a free wandering style. I have to update this as I level =p. The higher level maps are bigger, and the beginner zone map is smaller, but it still takes quite a while to explore everything. Some trails splits into 2 with one leading to another and one becoming a dead end later on etc.

How are the group dynamics? Is most stuff solo or is a group necessary?

Irisviel: It is possible to solo play, at least until level 18 or so. From that point though you probably should party to do quests since mobs got way much more hp and hit harder etc. I am not sure if it's possible to solo all the way to max level since people tend to party instead when their level is around +20 than solo questing.

Are spiritmasters at least viable in PvP? They look very interesting to play, but aerial PvP has me excited, and aerial PvP with an elemental would be the best.

Irisviel: Spiritmaster is probably the strongest solo class atm. not sure Aion Gold about pvp though. people duel and stuff but that's not real pvp so... we will see.

Regarding armor pieces, anything you can share?

Irisviel: about armor pieces, there are cloth, leather, mail and plate just like WoW. by using stigma it is possible for even casters to wear plate if you wish to, although it would be very stupid since plate armor doesn't give any mana bonus.

Hey, you are playing a Sorc, how are they doing against other classes right now? And is aerial combat in the game? Finally, are their invisible walls when you fly?

Irisviel: sorc is probably the highest damage dealer atm but they die very easily. sorc is pretty strong against melee classes atm in pvp but kinda weak against ranged classes such as ranger, although it really depends on how good the opposite player is.