3. No, but you keep gaining skill points after max level and you can trade the skill points for rare items and stuff like that..
4. There a TONs of cosmetic upgrades, in fact, most of them are cosmetic.
6. IMHO, combat in GW2 borrows much from PvP, which means that some PvE fight feel like PvP — your enemies dodge and play actively, you are required to do the same. You can't just stand there and do your rotation on the mob, you have to play actively. All skills I have seen yet are equally usable in both PvE and PvP. As the game lacks dedicated dps/healer/tank distinction you are responsible for all three and thus have abilities from the repertoire of all these three archetypes.
7. The gear stat difference is around 13% increase between each item tier, so the best items have 13% better stats then second best (which are very easy to get). This translates to 5% overall stat difference (when counted together with your natural attributes) so around 2-3% damage and somehow better survivability.
8. They are still tweaking the trading post - the economy is world wide and creating a system that can serve hundreds of thousands of concurrent players is a very difficult thing to do.
9. Crafting is nessesary to obtain rarest in-game items - legendary weapons. Best crafted armor is as good as best otherwise obtainable armor.
10. All stuff you can buy in the in-game shop (boosters, dyes etc.) also drops from mobs and is received as quest rewards. The only exception to this are vanity items like hats etc.
11. In GW2, you have a single one home server and your character limit is global. The home server determines your WvWvW side. If you just want to PVE, you can 'visit' any other server at any given time and play there. You can also change your home server, but this will cost money (AFAIK, its still free). The game chat is world-wide, meaning that you can talk to your friends/guild even if you are on another server currently.
From what you describe as your preferences, GW2 sounds like a game for you. BTW, try PvP out, its very much fun. You don't have to do it 'competitively'.