-There is no indicator for a backstabbing position.
Of course there is, the mouse indicator is changing to a knife to let you know you're on the right position.
It's more than enough to me, worst case scenario you're losing 1 AP to position properly but sometimes it costs 0 due to your quickness.
Widening the hitbox could be an option though.
The rogue is already VERY powerful making crits and all, mine is just very fine and does not need more indicator. And If I'm losing 1 AP, what are we talking about here...
The only thing I don't get with the rogue is the fact that the 50% +dmg talent does not seem to work when you're making backstabbing crits + invisibility.
I've tested it several time and my damage is quite the same when I'm invisible or not as long as I'm backstabbing.