I don't really go with the idea of making the stealth/hide skill into a transparent version rather than totally invisible. It defeats the purpose. Most especially in PVPs. If that is being permitted, then the only function for the hiding skill is to be unseen by monsters.
You forgot about Ranger's camo. XD
Agree that. And the 2x damage is ridiculous, Imagine you breaks invis by attacking and crit, that attack does 4x without the SM buff. For example Shadow Strike does 2.5k normal damage, if you go invis and crit with this skill, it will do 10k damage, that is whoopig 7.5k difference compared to a normal damage without a crit. Further more, Assassin, Rogue and Ranger tend to focus on critical hit build.
First of all, Assassin's are meant to be "deadly"; you don't see them fighting long battles while tanking (or shouldn't, in any case) but they hit once or twice, bringing death switfly on their victims. At least that's how I imagine a proper Assassin.
Now, I can agree that some skills (*cough* Cross Impact *cough*) are way too powerful, mainly because they can crit out of hide and we have a crit rate buff which makes them very powerful. But a change to this should come together with changes to other classes as well as we're not the only ones able to one-shot people.
As for the transparent idea, i can only say "precisely". Hide is meant to make things easier for us when dealing with mobs, finding a right position to strike, or even ignoring them. A real assassin doesn't kill all the guards of a victim, the target is clear, they go and get him. Now, that doesn't mean we can't find a middle point and say "let's make it transparent only on non-pvp situations", since i can agree it would rest value to the skill if we only have it for the double damage on pvp.. Even so, I've read that way too many consider stealth to be "cheating" if used on duels (which is dumb, if we can't hide, they shouldn't buff themselves either) and I think being able to see those pkillers in woe would help a lot.
