I've now been able to resolve this. I installed the game via steam (as expected) and it wouldn't launch, I then installed "again" via the EA app and selected my steam install location as where it should install to. It then did a small download which which was around 5gb and now shows in EA app with the steam icon and launches without issue.
Thanks for all the info, R4d1c4l - unfortunately none worked for me. I uninstalled and reinstalled both game and EA App, but the EA app wouldn't 'see' that the game was uninstalled and I got no option to reinstall. Well, it did take me to 'Get game' but that just took me back to the launch the game page. Sad, but forked out for the deluxe add ons (again) and at least now I have those. Still though the only way I can run the game is via admin privs on the .exe file itself. It's a pain, but it works.
