I have refused to answer any questions to "confirm my identity" on the phone.
I understand your position. Just remember the issue is primarily between Dwolla and TH at the moment. No need to put your own account 'in jeopardy' by being difficult with Dwolla since at this point, they haven't 'screwed' you over.
If they call, just ask if you would be allowed to call them back at the voice number listed on their webpage in order to verify your account/identity. That's it. They're not going to ask for more information than they already have of you when you signed up. (They just verified my name, address and phone #). Once that's done, make sure you've cleared your account of any funds, etc. *AND THEN*
at that point you can be vocal by ceasing to use Dwolla.
Dwolla at this point is playing 'catch-up' with verifying users before large ACH transfers to limit their liability for reversals due to fraud. I think they're learning pretty quickly what they need to do in order to reduce this. Of course, this doesn't excuse them from changing the ToS on TH (or for the rest of the users & business merchants for that matter) without prior notification and doing it retroactively, but they're trying to do some much needed due diligence now.