This isn't really related to your ban question but why not just run the NWZ Launcher instead of using Steam to run the game? You do know that when you download it from Steam the game itself is seperate and when using Steam to run the game there is a Launcher for that too.
You can find the Game folder for AvA alone by going to Computer>Local Disk C>Program Files (x86)>Steam>Steamapps>Common and the AVA folder is right there. This is for Windows 7 though. Not sure about the rest of the other softwares.
Then just go into the AVA folder and find the NWZ Launcher and make a shortcut of it then drag the shortcut out to your desktop and voila. You got AVA running on its own without Steam's help.
Now onto your ban issue. I'm not clear on this because the fact is I got banned on CA using steam but my steam account was never banned. So I'm not sure if this can correlate with AvA. You probably won't get your steam account banned though.