Is UserObject critical for Commerce Application to function?

Hi,

I am not planning to use the UserObject provided by the BizDesk
installation, in stead, I am using my owner table to store User
information and other related data in my Commerce Application.

Does any part of the Commerce Site rely on the existance of the
UserObject to function properly?  Example: will Shopping Basket still
work?
What will be the impact of not using the UserObject in CS?

Thanks ahead for any help.

Derek