we just added a loading screen tip about the hotbar and how to use it, it will probably get mentioned in an advanced game concept section as well... when re-recording the tutorial videos we considered adding a note to the combat video, however, we want to keep those very tight and it's not NEEDED to function in tactical. Every little bit we add to those videos makes it less likely people will stick through for the whole of them.
As a side note I would like to have a place we can show all those loading tips somewhere you can peruse them if you load quickly 
