Just my two pence worth and I am no expert by any means and neither do I profess to know Linux inside and out but . . . . .
I don''t see that you'll get too many replies saying it's not 'safe', I imagine it'll be the exact opposite.
As for 'back doors', I know where you're going I think, and again, don't see you'll get many negatives, the nature of open source
means there's slim probability that anyone could throw something dangerous into the mix without at least a few people round the
world cocking their heads to one side with a curious stare !
Lenovo ThinkPad T61 Linux Mint 12 Lisa & Mint 14 Nadia (on different HDDs) 2x Intel Core 2 Duo CPU T7500 @ 2.2GHz/ Kernel Linux 3.0.0-12-generic (i686) Desktop Environment - Cinammon 1.6/ Intel GM965/GL960 Graphics Controller.