Nice work O0
Great idea with the ice ring - I'll definitely experiment with the look and see how it goes. I'm always trying out little details like you suggested for the 94th's black falcon, most of the time it doesn't look right to me - but it's always worth a look.
I don't quite understand what you mean in your suggestions for the 3rd Talon and 305th Assault images.
Adding some 'shine' to the ice for the 12th Regulars is a good idea, but as you noticed I'm really going for a simple, spartan look. I feel the Clans (the Falcons, anyway) wouldn't go for lavish, ornate, heraldry for their units and to this end I'm always looking to cut out extra detail and colours.
In that vein I'm actually considering getting rid of the blood dripping effect for the 305th's ring in order to match the other three. Something still doesn't sit well with me about the look - I'm just not pulling it off.
The following are my interpretations of the Falcon Revival Galaxy insignias as described. These are essentially what I pictured in my head from the original sourcebook - before the versions were drawn up in later material. I think that before the Field Manual series, the authors of the original books intended that all galaxies had the same look, and just had greek letter and/or colour changes.
Gamma 'Jade Falcon' Galaxy: '
a diving jade falcon set against a shadowed white world'
Delta 'Gyrfalcon' Galaxy: '
a diving white falcon set against a shadowed blue world'
Vau 'Peregrine' Galaxy: '
a diving ash-blue falcon set against a blue-black world'