I am looking at installing Password Manager Policy (x64) and the Question is would I need CALs (Clients Access License) to cover all user's and is the cost per user or per Machine if I need one?
Password Manager licensing is based on the number of users accounts scoped in all managed domains. Users who are members of OU’s or Groups that have been denied access to Password Manager are not counted.
If the user count in your current license equal or exceeds the number of scoped users then you are okay. If not then you should contact your One Identity account manager for extra licenses.
As for Password Policy Manager, as long as you have a valid license, regardless of the number of users, then you can install it on as many Domain Controllers as you like.