[Space Communist]

Well there's nothing about the game being on steam that prevents it from being patched manually. The only question is whether or not Oleg and crew decide to release patches as file downloads as well as updates through steam. Certainly that was the case in IL-2, but obviously it was only added to steam much later. It's not clear whether or not running the disc version through steam would need the disc in the drive. Generally steam would not require it, however this game does not use steam DRM, but this solidshield business, so I really don't know how that works. Oh and most likely you will need to use steam to register the game to play it at all, though after that you could possibly play without loading it. Certainly you can play without being online

Anyway once it's on steam there isn't much reason to patch anything manually. If for some reason you really don't want an update you can disable automatic downloads.