I have a biometric lock on my safe and it is great! Well, as long as I am not missing any fingers!
Most people find the combination locks too 'long winded' and won't use them as often! Besides that, I have some tools that will open them pretty easily!
If you are just wanting to make it hard, then use the combination padlocks. There is a range that are 'TSA' approved, which means that they are able to be opened by SOME customs staff around the world, mainly the US. Otherwise, if they need to check inside your bag, they will cut it off!
I just follow the rule that whenever I get asked "did you pack the bag yourself" I say "no" lol
It is pretty well controlled. Anyone who works as a locksmith has to hold a police license. Not jut a clearance, but an actual license. Any history of dishonesty will exclude you from being able to hold a license. Personally, I have been in positions where I could have taken thousands upon thousands of dollars, in one instance, millions, but would never have even considered it! In saying that, I have no doubt at all that some people do take advantage of it.
As far as danger, I don't do crowd control or personal security, however there is a fair risk in some of the work we do. I have had to open safes for the police during raids, have to attend and lockout tenants etc. a fair few of those have turned violent!