Celtic Heroes

Is barbed shot worth using if you have the skill points? (Assuming already use sharp shot, double shot, steady aim, sharpen weapons at max)
Is it worth using on a raid or edl 6* if no expose weakness?
Should I use when Edl offhand skill active (8.2k attack unlixed) or would I lose too much dps from autos?
And lastly does it even increase dps when hasted (dl bow) or too slow cast time?

It is entirely dependant on how many other rangers are using barbed shot. If you are the only one casting it then by all means, yes it is worth casting. If there is 2 i would still use it however once 3 or more rangers are using it then that is when i would give it up.

Absolutely use it on edl 6* even if no expose. I found that it hardly missed and would tic up to 400 damage at edl with pierce lure. This is with a 50/50 barbed shot.

Idealy, i always try to cast it right before i cast dl/edl wrath and then cast again once it has expired. I wouldnt cast it whilst it is active. The loss of autos with wrath active is too great. That is with my 16k lixed attack. I am not too sure how it would be with around 10k lixed attack, i would have to do some testing to find how accurate autos are with the 10k but to be safe, i would avoid casting.

Whether or not to cast on haste depends. On a gele or vendor bow, no. Those weapons are too slow since barbed shot uses your weapons damage and delay when casting. With a dl, edl or necro bow it is worth casting because it is slightly faster.