Re: "There is no escape from collaboration"
We have only been using it a few weeks but I don't have all the issues that you seem to (I am running the Windows client).
In chat you can add multiple people to the chat, it isn't intuitive, you have to click a strange people icon at the top right of the chat.
I work in UK English, so type things like colour and haven't yet have it flag up anything that I have correctly typed as being misspelt.
I do agree that one thing at a time in one window needs to be resolved, and that there are lots of other things that can be improved.