Using Draw and Cancel as diplomatic tools is obviously okay, Pause is a bit iffy because the rules say it isn't a diplomatic tool, and it is to be used only when someone genuinely needs a pause, for important out-of-game reasons.
But honestly, give a desperate / frustrated gunboat player a button to click and he's going to click it. I use Draw or Cancel to indicate willingness to Draw or Cancel - this helps if you're leading, and want to reduce the chances of an anti-leader alliance. I use Pause whenever I'm frustrated with one of my immediate neighbors, like when he's attacking me instead of stopping a solo, and in my case, it is to be read as "Back off, ffs". Sometimes it's an indication of willingness to draw after draw whittling - like when you're the leader, everyone else hits Draw, but you want a little guy out of it, you could hit Pause and get the message across that you'll Draw if they take him out.
But as Vaft said, it would be unfortunate if any of these became standard, it would reduce the charm of having to guess what those votes mean, when they could, for all you know, mean that 15-center France needs to take a leak.