Are all skills questable?

Ignoring Elites, I'm wondering specifically about Aftershock, but in general, is any skill that shows up at a skill vendor at an out of the way place (Fishermans, Ice Cave, etc) available for questing somewhere in the world?

I would like to know the answer for this also.

Me and few friends wondered as well - so.......we compared our log quests to the skills traders in several places and most of those skills you get as a reward seem to be those offered by the Skills Trainers. The few that weren't on there are probably from missions we had not gotten yet. This was backed up when we got to Lion's Arch....we each had about 6 skills offered upon first arrival. However after doing various quests they had nothing to offer. This seems to be the games way of making sure you have access to all quests and if you miss a quest you can buy the reward (skills at least).

Vladiimir Dracu
The Gryphon's Alliance

No, they are not all available from quests. Some you have to get from skill trainers.

yeah and i think they cap at 40...i was capped for ages before i noticed i was capped...now i try to spend a few once in awhile, but i rarely come across a skill i want. skills seem to overlap...doing essentially similar things in slightly differrent ways. I'm definately not a skill collector.

a few elite skills intrest me and i've captured one, but i have to get to the fire islands for the rest.