1) is feasible and that can be done easily, but now I am a little bit fed up with PD simulations, so I will take some rest before organising it. Maybe anybody else is interested in running the competition?

3) Wouldn't it be easier to limit recursion depth instead of number of instructions? Not sure how to measure or even define the latter if the codes aren't written in assembler. The outcome would also be more predictable for the bots and would not motivate the bots to include something like "for (i=number-of-already-spent-instructions, i<9,999, i++, do-nothing)" at the end of their source code to break anybody trying to simulate them. (I am not sure whether that would be a rational thing to do, but still quite confident that some strategies would include that).