Hi all,
I’m trying to follow a guide for an Elementalist build, but it looks like I’ve chosen the Demolitionist first when I should have chosen the Shaman…does this matter as long as I just keep following the guide (I’m level 11 now) - or should I start again?
I guess what I’m asking is…does it matter which is chosen as your first class?
In the end it will not matter, but leveling the char will now be different. Just dive in, explore the game and learn from mistakes. 
Had you been 40 levels into the game already it would, but right now it should not be grave.
You should consult your guide though. Maybe it needs to unlock certain skills at certain level and wants a very strict leveling scheme. It should mention that explicitly if it does.
Not really, begin the build with demolitionist is quite fun. In term of clear speed, I think demo with stunjack and its upgrade is sufficiently fast and good for procing devotion.
Firestrike is decent single target and aoe attack.
For the first 10 level, it’s haedly matter.