I used to use the program I had in WRKSYSVAL QPWDVLDPGM to propagate
passwords from one lpar to another.
As far as other validation rules...
Many password system values are deprecated. Among them are:
QPWDLMTAJC *SEC Limit adjacent digits in password
QPWDLMTCHR *SEC Limit characters in password
QPWDLMTREP *SEC Limit repeating characters in password
QPWDMAXLEN *SEC Maximum password length
QPWDMINLEN *SEC Minimum password length
QPWDPOSDIF *SEC Limit password character positions
QPWDRQDDGT *SEC Require digit in password
and should be replaced by
QPWDRULES *SEC Password rules
You really ought to check out all the options in there.