Blu, unless you're extraordinarily strong, tightening the collars as much as possible by hand is safe. Pliers shouldn't be used.
Yeah. In my case they are pretty secure even without tightening the collar on my Axiom binding posts and those on my Denon. More secure than some other standard banana plugs I have used in the past that don't "lock".
Barely any strength at all is needed. You just want to screw the collar to the point where it feels tight and it will give that extra secure connection. I have never had to re-tighten them in the years that I have had them installed.
