You could do a Terminate and Transfer dialog component and send the user to the new link. If you want to pass a user name, you could use a URL parameter to pass the user account to the survey process.
As for the user verification process, I have created a Decision only process running as a webservice. That webservice has 3 methods, each taking a different value - DOMAIN\LoginName, WWID, or email address. All three return the same strongly typed data set consisting of all the relevant user data that may be needed in a process (for example - full name, email, telephone, manager name & email, etc...)
You could create something like this that takes in the user samAccountName and verrifies all the data is complete, and if not direct the user to some sort of remediation form to correct.
rob