First off, OP, you've done a really great job and takin' the info people put forth and actually listening to it and questioning it, which is something that's lacking on a lot of MMO forums.
There's a thin line of "meta" builds and their importance. But we also, as players, need to remember that having fun is important when you're spending time on a video game. I used a hammer on guardian since the game launched, cause I really kittening love hammers in games. But I also needed to make sure that my damage stayed within' a threshold that I wasn't dragging down "high - end" content and make someone else's job harder. I've been "maining" ele for about 2 and a half years now and have had a wonderful time. I think your choice of reading, understanding, and experimenting is important, as there are a lot of people who grab meta builds without understanding why. There are a couple of things in your opening paragraph that others have addressed, and I may hit them in this as well, so sorry in advance :P
People have pointed out that in terms of open world (OW) your build will be fine. And that's 100% true. You kill things, you don't die. You also play the game how you want to play it, which is very important. When you get to that "high-end" content is where this comes into question. People have pointed out that toughness can drag aggro from certain mechanics (especially in raids) and that can be hard to fight against. Also, the question that occurs is what does that extra toughness bring? We're eles. We're squishy as kitten. So the extra vitality and tough can be very helpful in openworld to survive a little longer, I get it. And I strongly believe in the model of you do more damage alive than in the downed/defeated stated, lol.. I run full Mara/dragons in my open world build because it's just more enjoyable to me.
When you have that full group/squad, that toughness drops off. It doesn't bring enough extra to the table over everything else. http://gw2skills.net/editor/?PGgAgilZwuYLsGGJOqOmtLA-DSRYLB5ZGNchnRCSgOUAK8YAL8+bBVA-e is a build I threw together that, is close to "meta" but also brings some more survivability to the playing field to be more enjoyable in high-end content. The difference between your previous build and this one is about 100 condi damage, which you get from the toughness trait, but a drop of almost 1100 power. Almost every ability that applies conditions does power damage of some sort. So having extra damage (even if you're not critting hard) still adds more to the end game. You've also brough up the crit chance. Crit chance doesn nothing for flat condi damage. BUT, there are many traits/sigils that work off of criting to apply something. Burning Precision works like this in the fire tree. The condi duration is also super important. Case in point, in the build you originally linked, and the build above, even though you have more condi damage, the burning from the build I linked above will end up doing more burning damage because it lasts longer.
The burning causes blind trait (Blinding Ashes) can work in OW, it just adds more survivability. But anything with a defiance bar won't be affected by blinding. So any high-end combat will find that trait worthless. Persisting Flame's Damage increase is only strike damage, but the longer lasting burning fields increases burning ticks, as well as the extra strike damage is, no matter what, an extra damage increase. Pyromancer's Puissance is a fine trait as well, because stacking might as a tempest isn't hard, and the explosions from switching out of fire does apply some burning.
Also, if you have the ritualist gear, you can some pieces of that on for a solid condi-alac build from tempest that can also be super enjoyable.
I want you to have fun. The way you want to do it. We're not gonna talk about "just Dodge" and there does need to be a justification for people playing the weapons/items they want as long as they're competent with them. I think that's the hard part that a lot of people forget when playing this game. It is a fluffin' game, lol. I hope you find your fun and enjoy the game how you want to!