Is it safe to rename the original folder which stores the iso and related VM folders of my VM without any issues being caused?
It depends on whether you've configured settings which point to other folders. Depending on what has been configured, the VMs settings may contain absolute paths, which would cause issues when renaming a folder.
André
Continuing with explaining this:
By default, everything of a VM is in one directory, even the additional disks, which have been created explicitly. Renaming that directory, doesn't mean much of anything. However, you should delete the VM from Library and open it again with Open selecting.
Sometimes, it complains that the Working Directory needs to be changed when you open up a copy/move VM. That is in VM settings.
ISO-file does not really belong to the VM. VM has a pointer in CD/DVD configuration of the VM and can the pointer be changed at any time, or made a non-active pointer.