i understand that free plan can add many users and they have certain GB storage etc.

if i pay for a "premium" and therefore have "admin governance" etc. i can add domains and users etc 

correct ?

so can i add/manage users/domains etc. for free under "premium" ?

in other words my "premium" email is me@domain1.com and i have also verified and set up email hosting for the domain,

can i add domain2.com and create harry@domain2.com mary@domain2.com and even tom@domain3.com and have them as "free" users ?

just because i create a "premium" account does that mean that every user i add have to be "premium" ?

can i not manage "free" users/emails/domains as well ?

your very kind assistance in this would be greatly appreciated.