Guild Wars 2

I run a 30/10/0/20/10 build and spend equal time in small scale and zerg pvp.
I also sometimes run a healing spec engineer (elixir infused bombs) but that is not the topic for this thread (important though because I can switch to it for bigger zergs).

In explosives:

Pros and Cons of Shrapnel v. Forceful Explosions?
When do you switch and how often?
I am starting to find myself resetting between the two traits before a fight.

In firearms:

Pro and Cons of Hair Trigger over Rifled Barrels?
Do you ever find the extra range better than the reduced cooldown?
Personally, I am not pulling out the pistol as frequently as I should I suppose.
On the other hand, I seem to be impeding a lot more from farther range (play a bit more backline then rush to bomb, then return back)

In Alchemy:

Big decision on the minor trait.
Invigorating Speed, Blood Injection of Protection Injection?
Does the size of the battle matter the most here?
What are the pros and cons that drive your decisions?
This is one I tend not to change (see firearms) for a fight because you really never know and I only have time really for a single change.

if you’re running bombs use forceful explosions. if just grenades use shrapnel. reasons are quite obvious.

always hair trigger over rifled barrels. the range is pointless. poison dart volley actually gets worse the farther you are from the target.

if you run energy sigil take proection injection + backpack regen
if you run something else like leeching or battle or whatever, take invigorating speed. never take blood injection.