Merge tags, User meta prepopulating drop downs radio buttons etc

I'm not sure why you want to register a user that is already registered. Do you mean that you want to allow the same email address to be used multiple times?

Can you give an example of where you want to use a merge tag and it's not supported? The merge tags are sometimes supported in areas where there is no drop down; you just have to type them in manually or paste them in in the correct format.

And, if you are talking about being able to update a user profile, have you already tried the User Registration 1.5 beta, which has a provision to update users, in addition to registering them in the first place?

I am not concerned about the email being used multiple times.

OK

Register an already registered user for the sake of creating more user meta?

In that case, you need to update an existing user, not create another user with a more complete profile, for the same person.

i have a user register in a membership plugin
i give the user privileged to access the gravity form that allows them to update all their user info - very complex many conditionals drop downs and radio buttons and some hidden field.

i have 1.5 beta and am attempting to use the registration feed or maybe the update feed to allow the user to get all their user info in somewhere.

You can create a form which pulls all their profile information in to it, then in the User Registration feed, you can choose to "Update" and existing user with this form

my goal is that I hope to allow them to fill out other forms with similar data using their personal info...i.e. member info necessary for event.

You mean you want to save them the trouble of typing their information into every form on their site?

i want my wp-usrmeta table updated with the meta and want my other plugins to see it - and i can see ti alaready starting to work, not sure if i need custom fileds plugin....

You can store all the user-related custom meta in the wp_usermeta table, using the User Registration add-on. These are not posts, so there is no need for WPCF or any other custom fields plugin. The User Registration Add-on can capture the information and store it as part of the user's profile (in the wp_usermeta table.)

s2members, gravity, wpcf, espresso

the example i am stuck on for one is how to put a default value user meta into a drop down field,

i have lots of drop downs for many reasons
and i have radio buttons.

how do i prepopuluate that?

Give me an example of the type of information that would be in a drop down for a user?

To populate any information in a Gravity Form, you can always use the gform_pre_render filter:
http://www.gravityhelp.com/documentation/page/Gform_pre_render

You can also use the gform_field_value_$parameter_name filter: http://www.gravityhelp.com/documentation/page/Gform_field_value_$parameter_name

With an example of the sort of information you will pre-populate in a drop down, for a user, from their usermeta, we can help you better with an example of how to pre-populate the form.