I'm going to preface this by saying I sincerely hope you mean pvp build, and not pve, otherwise I am going to weep.
I'm going to make a small list of general stuff, then go into depth a bit more. Obviously some of this won't be relevant at launch as things are very likely to change, but some of the concepts should be the same. Also, I'm not attempting to tell you how to play (it's your $12.95, etc.), just trying to give some insight. By no means am I an expert, but I've played Engineer about as much as possible for anyone outside of internal testers.
LET US BEGIN.
A.) You're really, really light on condition removal.
B.) Some of your traits don't SYNERGIZE
well with what seems to be the intended purpose of your build.
C.) Several utility skills (and as such, tool belt skills) can be replaced to give you greater utility (in a team oriented sense of the word), survival, and damage.
So first off, you need condition removal. For Engineer, this is best done in one of two ways: Formula 409
, and Elixir C
409 is a crazy-ass trait. While not mentioned in the description, it will remove one condition per ally hit, including yourself when you throw elixirs. That means you have the capability of removing five conditions from each member of your team for each elixir you toss. It's ridiculous, and I don't know how long it will last or whether it's a bug or whatever. Elixir C is also quite good, as it converts all conditions to boons, and the thrown version can help your team a bit.
Traits, skills, amulet, and runes will always be things that are very interdependent, so it does not make sense to talk about them without offering a build to exemplify what it do, and how it be.
is a build I've seen a heaving shit ton of success with. In spirit, it's very similar to yours. Bust caps in jerks, and hopefully light them on fire at regular intervals.
However, our two builds diverge very heavily in certain areas, so I'm going to go over the differences as quickly and concisely as I can to try and limit the wall o' text here.
Starting from the top:
Elixir H: Same. Heals and team support/condi removal, excellent.
Rocket Boots: Some people dislike them, I love them. Note that the tool belt skill is very similar to flame turrets skill, except more damage and a shorter cool down. The active also breaks immobilize which is great.
Elixir C: Taken over goggles due to goggles not being so great for condition based builds (they are excellent for power rifle, however), and use for condition conversion, removal, etc.
Elixir R: Taken instead of B because Elixir R's tool belt skill is overpowered. Elixir B is very nice, but the utility of Elixir R cannot be overstated. You rally allies (including yourself with some good reflexes) almost instantly. Breaking stun and refilling endurance are also very nice.
Supply Drop: Same, because it's the only good Engineer elite skill.
1st line: Same, this is standard for any non-explosives based builds.
2nd line: This is where things diverge. The Swiftness-on-crit trait is very good, and can probably be taken over what I chose; they do the same thing roughly. Pistol shots piercing is also very good and is what I would chose as well. However, the second trait, the one that applies vulnerability is detrimental to your build. Vulnerability does not help you much, but 20% CDR on pistol skills most certainly will. That's more poison, more burn, and more sticky-icky glue patches to infuriate people with.
3rd line: Cloaking Device.
This skill is literally the shit. Some Thief wants to immobilize you for 30 seconds with venoms and their plethora of pets? Doesn't matter; have cloak. I could go on. Immobilize is overpowered, and this will save you from it. If you have balls the size of China, feel free to remove this and place the points somewhere else.
4th line: If you're going to use elixirs, take the 20% elixir CDR trait, it's quite nice. Calling 409 nice is an understatement, but that is quite nice as well. It comes down to preference, but these two traits improve elixir usage so much, I find them too appealing to take anything else.
5th line: I leave that shiznit empty so I can take cloaking device, you take +25% endurance regeneration. Both are good.
So hopefully that explained some of the skill:trait synergy business, and all that remains is runes, sigils, and amulet.
I will start with amulet because you picked the correct one. Best condition amulet by far; toughness is very good and don't let anyone tell you otherwise. Be proud of your tough self.
Runes! You really don't need the extra precision; my set gives more bleed duration and condition damage. Again, my choice is probably not optimal, but I am almost sure it would perform better than slightly more crit.
Sigils! We have a shit ton of bleed duration anyway, the 10% off agony isn't super important. What is super important, however, is a certain distinction about sigils.
Some stack, and some do not. For example, these
will only affect the weapon they are placed upon. You will not get +10% damage for both hands, only +5% per hand. This is not the case with the sigil of superior earth.
Any crit, with either hand, may proc these. Only one sigil will activate per crit, but they are amazing. Your poison dart volley
in particular becomes deadly when using these. You have a roughly 84% chance to proc a 5 second bleed (that has no cool down wololololo) per crit, a ~50% crit rate, and five hits on a skill that's up every eight seconds. That also applies poison. Think about that shit, bro.
That's really all I have to say. Hopefully someone will make use of this. Again, as always, I may be wrong about anything here and am happy to be told I am wrong, suck at the internet, suck at life, have insufficient genitalia, etc. Suggestions and comments also welcome.