Where can I find a free list of pre forclosures for Dallas online?

There is no such term as "pre foreclosure." A home is either not in foreclosure or is in foreclosure. Generally when a home is foreclosed upon the bank will list it with a Realtor. You can probably go to the court house and get a list of homes that are in the foreclosure process. But that probably won't help. Most homes are in foreclosure because they owe more than the home is worth. You're better off to wait until they're listed because no matter what the mortgage balance was the bank will list it at market value.

You probably can't. "Pre-foreclosure" has no legal meaning. Watch the legal notices section in the local newspapers. Once published, the foreclosure process has started. If anyone consolidates listings like that, they are not likely to give them away for free.

In reality they won't be for sale until after the foreclosure is complete. At that point the lenders turn them over to Realtors to sell them off.

The other option is to have local Realtors look for short sales for you. Those are for sale for less than the outstanding loan amount. They need the approval of the lender, which can take several months to secure in some cases.