Can we skip the membership provider

I am just wondering, can we skip the whole membership provider.  At first I was going to implement a custom one.   But I use a totally different set of user feilds than it does.  At first i thought I would just overload the methods.  but then I can't access my overload.   membership.provider.myoverload() isn't availalbe.  If I use a method that is defined in the abstract class cool, my provider works.
If I skip the whole membership provider, what do I need to make sure to do in these methods in order to still have the authentication attribute and so on work properly?

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