multiple (two at least) user registration forms I have built a registration form with a few custom fields, works fine. Now I need to another registration form, but with a dozen or so more fields. Both need to force drupal into its user registration/validation process.

it has to be done this way, I cannot just redirect a user to register first then fill out a survey.

Alex
You can achieve this using Profile 2 and Profile2 Registration Path module. 

Profile 2


  Multiple profile types may be created via the UI (e.g. a general
  profile + a customer profile), whereas the module provides separated
  permissions for those


Profile2 Registration Path


  This module enables administrators to set unique registration paths
  per Profile2 profile type