I think the HUD chat window activation should be changed to be similar to the "Target", "Activate", and "Mission" buttons at the bottom of the screen. By this I mean that it should be configurable with a long-press, allowing players to change the default chat channel they communicate in when not using the PDA (Channel, Sector, Group, Guild).

This would make it simpler for mobile players to engage with others through more appropriate means of communication and would open up the virtual keyboard macro keys for other commands (assuming they're currently being used for various /say_ commands).

So, just for clarity.. you're saying that someone long-pressing the chat window field on the in-flight hud would then result in some kind of "channel option" slide-out, which would enable selection of the default chat transmission (channel, sector, group, guild) from then on?

Correct.