Is this a situation where you may have over promised and can't deliver?

There is NEVER a reason to create extraneous liabilities for yourself.

Part of your job/responsibility is to level with your client about the realities you have explained to us.

When you manage risk, I don't think it is realistic or smart to sign your name with absolutes.

Sure you can minimize risk which I think you are doing but be careful about absolutes......

What is the application by the way? Is there a database involved (even flat file)?