The current ICA Client ebuild does not copy/create the empty .server file in $ICA_ROOT/config. This .server file is required for the ICAClient to know to use a local .ICAClient directory to store configurations (drive mapping, etc). Without this file, the icaclient assumes $ICA_ROOT is where the configuration files are stored at, which makes it entirely unconfigurable by non-root users.
Good catch. I have the fix incorporated locally. I'm holding off on commiting it until I have a fix for bug #65732 as well. Hopefully only another day or so.
Now in portage in icaclient-8.0-r1. Thanks for the bug report :)