Best pvm single target: any class played well. All of them have the tools, you just have to play the game well and stat/gear right.
best pvm aoe: DK destro staff. Race bonuses don't actually matter in this game, they're incredibly tiny.
PVM tank: prob dk sword/board
PVM healer: Templar, hands down. Resto staff ofc
They're coming out with sub rewards, have to be subscribed for a certain amount of time to get them.
AD most popular, DC least.
No clue what this is supposed to ask
motifs 1-9 are a few hundred gold, the rest are still pretty pricey, 15-35k
Game has a pretty healthy population imo. Easy to find a group for dungeons, though I'd recommend playing through it with someone.
Gold/mail spammers are nonexistent.
Bots are also fixed, can't get xp/loot from bosses for some time after you kill it, so cave camping is no longer a thing.
Tamriel Foundry Tactical Combat is really the only "must have" one because it gives you numbers in combat and % stats. Other than that its just personal preference.
If I can recommend one thing, idk if you've already done this or not, but make any char you want, doesn't have to be optimized, and just play the 1-50 content. Then make your "main" char and you'll have such a better grip on how the game is now and won't make mistakes at the early levels nearly as much. Also, the one thing I noticed your neglected was crafting, and my advice for you on that subject is this: start immediately if you're going to do it at all. If you can, (and have some gold) find someone who is selling traits to research and get them to mail you all the traits that are researchable and start straight away so you can start those timers soon.
Hope this helps, feel free to pm me. Or, you may find this place MUCH more helpful than d2jsp (at least for eso matters):
http://tamrielfoundry.com