WordPress Membership Plugins/Queries

Hi,

Hoping somebody can assist with the following queries or perhaps point me in the right direction:

1) I am after a decent/secure User Registration plugin for new users as well existing users to login.

Basically require a means for new customers to create an account as well as existing customers to access their account.

2) Based on point 1 above, I then would like them to be able to provide details of themselves based on specified questions, like a form entry screen for new customers. Existing customers can edit existing details? Perhaps Gravity Forms?

3) Based on the above points, I basically need like a workflow of a user creating a new account in the system or login to their existing account and only see details relating to their account ONLY – unsure how to do this in WordPress? Any plugins to do this/ideas?

Basically, I will need like a generic page within WordPress where 1 or more users can setup some type of info, after registration, that is just restricted to a specific user logged in.

Is there a means of having just one page in WordPress but restricted on a per user logged in basis?

Obviously this will also need to cater for user’s that may have the same name but are obviously different users?

Hope this makes sense.

I don’t want to set up individual pages per user as this will be a manual process and I will not know exactly how many users are registering.

FYI, am also willing to pay for plugins if required for the above.

I am also not sure if wordPress can achieve what I am after above but I really hope it can.

Thanks.