backing up wince on a sharp hc-vj1c

I just found this little beauty under a pile of stuff in my computer room, I
forgot I had it.

I'd like to take the plunge and try to install NetBSD on it, the
instructions seem to be pretty straight-forward, but...

I can't find any real info about WinCE anywhere, I know practically nothing
about it, which probably wouldn't help me much even if I did, considering
the OS on this machine is all in Japanese.

1. is it possible to hurt the WinCE installation by loading NetBSD?
2. how do I backup and restore a WinCE installation?
3. can I permanently load NetBSD on this machine (and never have to deal
with WinCE ever again?)

I may not keep this system, so I would like to not do anything irreversible.

Thanks!