AIX minage & maxage & rlogin in default & indiv ids

In /etc/security/user,  we have
default:
      admin = false
      login = true
      su = false
      daemon = true
      rlogin = true
        . . .
      minage = 1
      maxage = 8
      mindiff = 3
      maxrepeats = 2
      dictionlist =
      pwdchecks =

oracle:
      minage = 0
      maxage = 0

infrauser1:
      minage = 0
      maxage = 0

sshuser:
      admin = false
      maxage = 0

infrauser2:
      minage = 0
      maxage = 0


Q1:
For infrauser1 & 2, shouldn't the minage=1 & maxage=8 to match with the default & security best practice?

Q2:
with min & maxage=0, for these 2 infra users, do these settings override the system default's minage=1 & maxage=8 ?

Q3:
For oracle account, what's the best/secure practice out there?  min & maxage=0 ?

Q4:
for sshuser used to do sftp, what's the best/secure practice out there?  min & maxage=0 ?