Damn! Sorry to hear about your gear loss mate! I think with all the freedoms bikes offer us, it does leave us vulnerable at the same time.
I use my bike almost exclusively for touring which is I why I ended up going to all the trouble of building a set of secure, lockable panniers. Now, when I stop somewhere to explore, I can drop my cam and navigator in one for [relative] peace of mind.
One thing I won't do is carry my firearm, makes would be villains nervous and do silly things things like shoot you (at least where I come from). I carry a neat, powerful pepper spray close to me which can (and has) been useful.
Regarding cameras, have you tried a helmet mount? I find it much more stable and I never leave my helmet on the bike.