Sorry it too me so long to respond.
I think you ought to start again from scratch.
There's a heck of a lot of new stuff in XenForo 1.2.
One such thing is Template Modifications which basically enable you to specify a template, find some code within it, and replace it with your own code. It's much easier and much more flexible. Template hooks are officially deprecated. And although technically they should still work, they aren't as favourable as the Template Modification system.
Also, as the contact information is now stored in custom fields, you don't even need any custom PHP to fetch them.
Once you've added your template code using a template modification, you can get the value of a user's Twitter account using:
Code:
{$user.customFields.twitter}