Training trait question

Chelister

It increases experience gained from kills. Does such boost to exp also count to skill or skill tree levelling?
I know that your level will progress faster with the trait, but what about the skills you are levelling?
And also, will the trait increase armour skill line progress?
It just says that killing mobs increases experience gained, so I was wondering whether it counts to more than just character level

idk

The trait increases XP from kills which helps everything that levels off XP.

It will level armor based on what your wearing. Skills on the active bar when the XP is gained along with the weapon line active at the time.

Azurya

Yes they do! Try to find someone creating some set parts in blue, there you can wear them for 10 lvl´s, as I do when I lvl any new Chars.

Nestor

There are 3 kinds of PvE Experience in this Game:

1. Quest Experience - Counts towards Character and Active Skill Leveling. Active Skills being the ones that are on your bar at turn in
2. Mob Kill Experience - See Above
3. Crafting Experience, known as Inspiration. Counts towards leveling your crafting skills, as, well, you can't slot those so something has to be done.

The Training Trait increases exp from mob kills only
Exp Potions and Scrolls increases Experience from all sources, but not Inspiration
There are other ways to boost Exp gains such as grouping with one other player, special events, Rings of Mara, ESO Plus etc etc. You can increase Inspiration with a Champion System Passive and ESO Plus too.