I'll avoid trying to answer your specific questions because I don't do airways and it 's probably best to leave it to an area bod. But the UK radio comms failure procedures have recently changed quite significantly.
Although the begining of
this document is aimed at ATC it does include the revised radio fail procedures in an appendix - para 3.2.4 is the all important bit. Just a warning - it's a long download, about 1.5 meg.