If you ever watched Zeorymer, you'd know its "of the Heavens" actually represented its OVERWHELMINGLY DOMINANT POWER. KA-BOOM! The wind mech of Zeorymer was Lanstar of the Winds, piloted by Taiha. It was pretty much exactly what you'd expect a wind mecha to be like (fast, agile, and slim with the armor).
For Cybuster, the biggest reason its attacks aren't windy-themed is Masaki's simplicity in using prana in general. He's actually pretty uncreative at it, possibly due to his origin as someone who grew up outside of La Gias. Thusly, all of his attacks either involve sword arts (which come from his diligent personal training in physical practices) or gathering large masses of prana without creative form or application. For Akashic Buster he gathers a lot of prana around himself and then charges with it. For Cyflash he gathers a lot of prana and then lets it all loose as a big explosive release. For Cosmo Nova he gathers four masses of prana and then throws them. I think in one of the games he even charged his sword with prana and then used the sword to fling the energy away. All his other attacks are either strictly sword-arts capitilizing on the Cybuster's high innate speed and Masaki's amazing skills, or the caloric missle.
So it's not really that the Cybuster is incapable of wind attacks, it's just Masaki is bad at magic in general, which isn't really unexpected. It's ok though, because Cyfis likes him all the same.
And as for the A-in-air rank, why is this a surprise? Humanoid form is battle mode, and a differentiation had to be made to give "flight mode" its superiority. Bird form couldn't be SS in air, after all, so the Cybuster has routinely been treated like a Macross Valkyrie since its first appearance, with an A rank in air similar to the Valkyrie's battleoid form.
Bane even prayed for Dick when he became Batman. -- Frostbite_Zero
Cybuster's design is mostly based off Dunbine, along with the magic bit. (SRW 2 was orginally supposed to have Dunbine which didnt happen, and was replaced by the Cybuster, in addition to the Valsion and the Granzon. It could very well be that the Cybuster was designed before they really knew what to do with it.