If the bar stock is fully contained within the spindle, and a spindle liner, there is nothing to fear from whipping.
If the chuck is in balance, and has jaws, it will have an rpm rating to warn the operator from overspeeding, which could throw a jaw, or open the grip of the jaws enough to loosen the stock.
I don't know what kind of collet chuck you have, but typically, a collet chuck is fairly streamlined, not too massive. It should not be too scary to spin it at whatever it will take. You will have a break in period while you get used to it. The machine doesn't care
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)