g using q as hotkey is a bad idea
the key Q is per default used to remove items from your hand and to change weapons. When you have a chainsaw, my tool slot switches tool and chainsaw whenever i remove an item from my hand. Also I can't switch my other weapons anymore with your chainsaw mod. I suggest using another hotkey to switch tools with your chainsaw.
The devs changed the change weapons from Q to TAB in 0.15 for some reason, so the only thing in the way is the remove items from hand and I don't see how they could affect each other.
You probably only have problem because you're still using the same config as before.
And then I would suggest you just go in the setting and change the shortcut for the chainsaw to something you like.
I guess I should add a check to make sure your hand is empty before switching.. i'll check to add this.
I didn't notice the pipette tool is now on Q so I will just remove the default key and you can pick the one of your choice because I don't see any good alternative and I'm tired of trying to find one.