Guild Wars 2

As I’ve stated in most of my previous posts, I’m relatively new to the game. According to my /age 21days. I’m beginning to better understand the game now and currently have 2 level 71 characters (stopped working on my Engineer in favor of a Thief but I plan to bring them both to 80 this week.) However, I’m still a bit hazy on how to properly build a character. And because I spend the majority of my time in WvW and am a very competitive person there, it’s important I’m as effective as possible. So, my questions are:

1. As a thief I would like to fill the role of annoying assassin. I don’t plan to nor did I make this character to be a troll, -but I do want to have the option of being able to sneak around and snipe off the enemies I see lagging behind the zerg. So what would be the best traits and skills for me? I found this page that I’ve been using to guide me but a bit of outside advice on whether it’s a good guide to follow or not would be great.
http://intothemists.com/calc/?build=-cF33RBF_w-_07-VOVd0;9;5JTJ;207-34A08;24FG0JJF0JF04JF045Bt

2. As an assassin, I want to deal as much damage as quickly as possible. I’m extremely fast with this character and have really gotten the hang of running in for a stab and taking off. But I don’t do quite enough damage yet. So what kind of sigils and runes should I be looking at? Precision and Critical Damage? Or would there be better options for me?

3. I’m almost positive I’ve misunderstood something about stealth. I see thieves going in to stealth for long periods of time all the time but I can only ever manage a few seconds. Have I not filled the right traits or am I doing something wrong with my skills?

4. Not related to build but still something I’m curious about; The Ruined City of Arah is apparently where I earn Shards of Zhaitan. I would like to do this so I can purchase the Orrian Reward set. I love the fur and hunter look of the Norn and that set really fills the bill for that style.

5. And finally, I purchased 2 Exotic daggers for when I reach level 80 which hopefully will be by the end of today. Will exotic be an okay weapon to roll with or will I be largely outclassed by Legendary?

I apologize for any stupid questions I may have asked but as I’ve said I’m still relatively new.

Can’t help you with the class related questions, but yes Arah Explorable gets you shards of Zhaitan, it’s a more challenging dungeon so be prepared. I believe there’s a 10% stat difference between exotics and ascended/legendary. It’s not a huge difference, so you won’t be hugely outmatched.

Arah is not that bad once you’ve run it a couple of times and know what to expect. You could watch some videos of other people’s runs but nothing beats actual experience.

The difference between Ascended and Exotic is 5% for weapon power and each individual stat. The total number stat point differences might be 10% but that sort of comparison is about as useful as the Attack stat.

You should also check out the Thief and Engineer class forums. More specific discussions on builds goes on there. (At least in theory, I don’t frequent those places myself.)