Ehe, I saw "other people" and got my hopes up that Tamonten wasn't the only one who was immediately mauled by sneaky wolves.
My character can probably still pull through despite that run of bad luck (it was at least partially bad luck, as you said my character only had a 30% chance of not noticing the stealthy lot). Of course, if my character didn't have a high body stat she would probably be receiving the traditional 'Artmirst Welcoming Committee' party right now. I wouldn't say that sneaking is much too strong though. The worst thing about the stealth attacks was that at x2 damage it was essentially the same as being hit by 5 wolves on round 1 and included one from the wolf that was spotted. I think if stealth attacks (at least from monsters) did automatic maximum damage or normal damage roll + 1d# then the stealth mauling would be a little more in line. Or if the spotted ones don't get to take part in the round 1 sneak attack. Then again, I haven't seen anything more intense than wolves yet.
Regarding grapples: I have no clue. Things are already looking pretty rough for the characters that got grappled.