Okay I think I sorta got onto a track to solving this. I didn't realize pointer is a thing you can get values from...so now...the canvas has this for it's drag code:
on drag pos do
me.parent.pos: pointer.pos-(me.size/2)
end
BUT it also really jerky, so I'm just working on that part now. I'm assuming because the mouse moves? So I'm going to try the 'pointer.prev' and see if that makes a difference in the meantime...