For AXL, you can create a new user group in CCM User Management, and then assign the 'Standard AXL API Access' role to that group. This allows full access to AXL, there's no more granular permission available.
For CAR, you assign users to Standard CAR Admin Users to give them admin access.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.