Speech is a poor way of conveying safety critical information - we should be using a datalink system.
Aviation uses Amplitude modulation - an inferior system.
Too late now but when 8.33 khz was introduced a channel number system should have been utilised - eg call XXX on channel "Eight Alpha" rather than all these numbers.
If aircraft were fitted with "Contran" this would prevent simultaneous transmissions and repeat calls etc.
Good idea about FIRs on the EFIS and yes using FIX is a good plan and we should be aware of where the FIR boundaries are and prompt if no handover.
Totally agree about the sectorisation but with the traffic densities around now is there any other way of doing it?
Surely modern technology could address some of these challenges? 121.5 monitoring could perhaps be done on a SELCAL type system?