Create custom user signup form for each child blog with no redirect

Hi,

I am running a MU install (with buddypress deleted) with multiple child blogs.

I would like each child blog to be able to add users that:

- Get access to that child blog (contributor access, but all other childs and main just subscriber?)

- Never redirect to main site for the creation of a user

- Would also like anti spam captcha even though Aaron on another topic said it is only for new blogs

- More user fields so their profile page actually has interesting info

The top 3 are high priority at the moment. I just want a flowing new user process for people out at child sites.

Cheers,

John