I wonder if it would make sense to add an option in the installation window, asking if the specific koha installation will be used to host latin character records only, or if it will also host biblio entries in other, non-latin-charset languages. The installer would then install/enable/parametrise components [ICU] as needed in order to properly accept, index and search such records.
The web installer is too late for that, as the files will already have been put in place when you run it, but there is an option for ICU in the tarball installation (bug 7698). Maybe we should add an option to the debian package installation as well? Changing bug title.