I upgraded to EoD after like a week of playing, simply because I was so hooked. It's already been worth the money, I've got like 150-200 hours in the game, and even in this short period of time they've made some really great changes and additions with every patch. With the wipe we'll get the new map, which looks fucking amazing, and supposedly they've used new optimization techniques on it, so hopefully performance will be good. There'll also be a ton of new content with that patch.
I loved doing most of the quests myself, they gave context and added excitement to raids. Having an objective, and having to survive, was pretty cool. Of course that's only the quests where you do something intelligent. Those grindy "find 10000 rare items" quests are dumb.
Level 3 traders is definitely enough. The "omg I just get raped by fort+fast people ;(" complaint is pretty common, but the reason those people get raped is because players running fort+fast are almost always more experienced, not because their gear is better. I myself run PACA+Fast with visor these days. 6B is almost as good as a Fast, and a fuckload cheaper (2000 dollars for fast+comtacs+visor). Only thing you're really missing is RSASS, which is really good with the M61 ammo. You completely ignore every kind of armor. But AKM is my favorite gun regardless.
I just wish they'll tone down the aim punch they added in 0.7.6. It's a bit extreme. But because of it, Fort armor is especially bad now. If you get a bead on someone, it's unlikely they'll be able to return fire effectively no matter what their armor is because it doesn't help at all against aim punch.