Okay, I've got a 300 point Modern event coming up that's intended to be competitive. I'm considering running the Trinity of Sin teambase at 300 points, but with all the Flash pieces instead of the box ones. The only one I'm considering changing is Question, but I haven't really played with the base enough to know what to do with it.

1) With only 3 characters, it seems like pop offs are a bad idea. On top of that, the double Mystics is a really nice icing on the cake. I probably won't RELY on that too much, but it's a great benefit.

If necessary, not worrying about the Asset dial and popping-off Question to Outwit certain powers (reducers, Invincible, etc.) seems like it could be helpful, and keeping him Outwitting will keep him from getting stacked with action tokens.

2) If I choose not to pop-off, then the question becomes what the best Asset dial option is. The (1) gives me some versatility, for sure. Sticking with the Flash ones though gives me this on the Top Dial:
Pandora: Precision Strike and +2 Range (a total of 10 Range without any other modifiers)
Phantom Stranger: Steal Energy at 0 Action Tokens and Regeneration at 1 Action Token.

These are both good. Precision Strike helps get around Super Senses and gets me in through reducers for at least 1. Regeneration helps if I get down too far for comfort (though I do have three clicks of printed Regeneration at the very end). Regeneration and the double Mystics is also really good together.

In my opinion, the best combination (sans pop-offs) is Question + Pandora, but the asset dial is mostly random and that combination exists only on clicks 7 and 9 of the asset dial.

I'm not gonna lie, I am not a fan of the ToS base at 300. At 400 it's a monster. I think id be tempted to run both Questions and Pandora(from the base) as individual figures.