This is something that I've seen in multiple locations, heard from many
experts on security, but having never experienced a system operating under
this set of guidelines I don't know what it does to the functionality.

Many many times I heard experts mention locking out all default system
accounts. Both changing the default shells to /bin/false or just
eliminating the field altogether. But for AIX, what are the ramifications
of doing that? AIX has some curious default accounts at ver 5.2 - snapp,
invscout, and this other one - root. What's up with that, I mean disabling
root is the first thing I do to the system (sorry I'm being sarcastic).
Anyway, bin, sys, daemon I can disable those without too much hesitation,
but what about uucp or nuucp? Would changing uucp's default shell to
/bin/false hurt the system down the road? Anyway I'm just kind of curious
what all everyone else's experience is in this matter.