No, no problems riding other bikes without hands.
I grew up doing it.
It's a Gary Fisher Marlin, with the Genesis geometry. I don't know enough about geometry to know whether this bike should ride like that or not.
How does the geometry affect riding without hands? Is it because it is meant be able to change direction very quickly, which would require it to be less stable than a bike which is meant for long term straight forward riding with very few turns? I just never thought of this as being a bike that was built for that sort of thing. I don't even know if my idea is correct. If it is, is there anything I can do to make it a little more stable? I know, it's quite a longshot, but it can't hurt to ask.