That's why I use Steam Achievement Manager. I want to play the game, not the achievements. Version 4.0 works with the scout update. Do some searches and you'll find it.
As far as I can tell, you can't attack when you're under the effect of "Bonk" and you still take damage. I was hit by rockets and killed by a turret when I last used it.
The new shotgun seems very weak. You get 2 shots before it has to reload and the shots seems to do less damage than the scattergun. The loss in killing power doesn't seem worth the increase in mobility.
The new bat is fun. I'm not sure how effective it'll be in the long run, but it's an interesting concept.