I totally agree with your comments, what concerns me also is that in their T&C's they definitively state that they will carry legal limit airguns, they have then said, in recent communications that air cylinders are not acceptable even if empty, "due to the automated sorting processes" They will, however transport guns sent by RFD's via the same systems!!
I am awaiting a response to my questions about this and requesting clarification.
The bottom line is that even if it is clarified, the compensation clause finishes it off anyway. F2F or RFD is the only way.