These questions seem decidedly UNfair to me.

No, they don't depend on the agent's decision-making algorithm; just on another agent's specific decision-making algorithm skewing results against an agent with an identical algorithm and letting all others reap the benefits of an otherwise non-advantageous situation.

So, a couple of things:

1. While I have not mathematically formulated this, I suspect that absolutely any decision theory can have a similar scenario constructed for it, using another agent / simulation with that specific decision theory as the basis for payoff. Go ahead and prove me wrong by supplying one where that's not the case...

2. It would be far more interesting to see a TDT-defeating question that doesn't have "TDT" (or taboo versions) as part of its phrasing. In general, questions of how a decision theory fares when agents can scan your algorithm and decide to discriminate against that algorithm specifically, are not interesting - because they are losing propositions in any case. When another agent has such profound understanding of how you tick and malice towards that algorithm, you have already lost.