If you joined, your company would retain it's autonomy to a large degree - becoming a sub-corporation of SteelCo, and you yourself being both CEO of your company and a member of the 'upper echelons' of SteelCo (Some people say it's like a cult; at the Executive level). Given the chiefly independent nature of the SteelCo Executive level members and the expectation that members will raise and manage their own 'contribution to the cause', this would partially be the case anyway.
So in answer to your questions, you would be managing your own affairs and contributing to our effort largely in your own way, except when I require the Executives to combine their efforts for a greater purpose.
And, given that you are the manager of a company, and possibly soon to be Executive of a very powerful organisation, I'm sure you can purchase pie yourself.
One note, other members of SteelCo - you are advised to consider how best to contribute to the struggle for the Hill, be it military manufacture, combat training or some form of research. Do what you can - and remember, I have the magical side of things mostly covered.