Hey all,
Really sorry for the delay today but finally managed to get it working. I'd spent all day trying and gave up about an hour ago. Was in bed when I thought, 'Fuck it', and asked AI a quick question on my phone, and that ended up being the solution to all my problems :P If you're a dev and have to use SteamPipeGUI... Just don't! Ask AI about it and create a .bat file to bypass it; it worked like a charm :P turning a 12-hour stress-fest into 2 mins of bliss.
Ugh, sorry for rambling; I'm just happy it works :p if you find any issues or errors or just don't like the game, let me know :)