Setting your own goals sounds logical and great. Can't wait to jump back in, don't get me wrong, I'm enjoying the fuck out of this game.
To give some examples, here are a few I set early on and then closer to 80.
-Fully explore (zone complete) Lion's Arch and do its jumping puzzles (although I realized much much later there was a third)
-Fully explore Metrica Province (this is the Asura newbie zone)
-Get my jewelcrafting to 200
-Save up for and purchase black dye
-Visit Ebonhawke/find gw1 easter eggs
-Take a keep in WvW
-Gain a level in a zone far, far above mine (got two in Frostgorge Sound somewhere are level 50, was a rush)
Later goals I started working toward closer to 80:
-Get the exotic/dungeon weapon sets I wanted and upgrade them (sigils)
-Get the armor appearance and stats I want (this has become a much more involved and expensive ongoing project than I predicted)
-Get my jewelcrafting (done) and weaponsmithing (not even close) to 400
-Master certain dungeon paths (there are individual mini-goals I set for myself inside dungeons too, like beating a certain boss without dying once)
Punctuated with WvW, non-goal-related dungeoning, Meta Events whenever I came across them, a bit of playing the market and the mystic forge, and playing an alt I just got to level 55 last night.... end result being that I'm only on my level 50-something personal story quest with my main character because I got so caught up with stuff to do. Really need to finish that up.
I should also note, if you find the combat getting a little easy or mindless at any point, my best moments leveling came when I was in zones that were 5-8 levels above what I was "intended" to be doing. Love the challenge.
Suggestions? Besides me just not sucking
I can't offer you much in the way of "do this" because I know nothing about engis, but as a thief I can tell you two things:
1) The experience you had (essentially not even getting a real chance to fight back after you catch sight of us) is exactly what we try to execute in a 1v1 situation
2) That motherfucking flamethrower completely renders stealth useless and wrecks the shit out of me. Even though it doesn't do that much damage, nullifying the advantage of stealth disorients and pisses me off enough to lose a lot of the time after I get caught.