1. Aion is easy to level in now. The semi grind is with gearing out, however you can get a Blood Mark weekly/daily LV 65 set which is what most people use within a few weeks. The hard part is manastoning/enhancing it. It takes a lot of money, which also requires some farming (time) to get.
2. There is plenty of pvp at most levels. You can participate in sieges at 25+ (levels vary depending on which zone - such as lv 50 sieges, 65, etc). You can also rift or do open pvp in abyss at 20+. The PvP in general is very fun and there is plenty of it to be had. Don't forget the Dredgions which are 46+ which ensure at least some AP for participating, and is a good mix of PvP and PvE. It's a tactical instanced pvpve zone.
3. You could choose a craft, and also gather materials you find as you level. You also can get a house/apartment and decorate it as you like. You can also do plenty of dungeons to get nice gear as you progress. There are many dungeons. Also, at 30ish you should be spamming the Silver Coin repeatables so that you can get a full yellow LV 36 coin set. You can find the weapons/armors for a discount coin-wise at the 'Elyos Base' in Eltnen or the 'Asmodian Base' in Morheim.
4. You can use dual daggers or dual swords, or mix and match them. The class you're thinking of is Assassin. You could also go Ranger which uses a Bow. There is also some newer classes including ones that use pistols (Technist/Gunslinger) or ones that use a harp (Muse/Songweaver).
PS: Don't play on Aion EU if you want to enjoy yourself. NA is a lot better, and it's actually truly free, while EU has a gold pack which is basically a subscription that removes most limitations. NA is not limited at all.






