It appears to me like you are looking towards building your own ISO with a package set more suited at your preference.
It is fairly easy to do - and the community have worked out a couple of documents and videos explaining the process. The following is a short introduction with links to more viewing
- Official Document Building a custom ISO image for X86
There is two text files in the systemroot which is lists of packages provided by the ISO experience.
- roofs-pkgs.txt (common to all ISO)
- desktopfs-pkgs.txt (environment specific)
The topic on [root tip] [How To] Do a manual Manjaro installation describes a method to parse those files and install them to a base system - but the method can be appiled for other use cases as well - such as reworking a running installation.