I am new to turning, and my work would require me to sometimes use recycled wood. Previously, I turned a few ballisters to repair a rail on someone elses lathe. I didn't kill myself, by way of common sense or probably luck.

According to my training (rotational moments of inertia blah blah), I am afraid of a lathe that has a starting speed above 300 rpm. Most of what I would do might be long, possibly thick stuff. Is this a valid concern?