1) Path of flames is much better because it gives you range. Everything is melting in the tantrum zone with or without a belt anyway. Gives you better performance vs phys immunes. Also you get perfect utilisation of the superbeast spell damage & euphoria pierce.
2) If you can cap the pierce with it, bag of tricks deals more damage indeed. The reason I prefer hanabigami endgame: 1. You can make multiple copies of it and roll for an azmodan lottery (mine was upgraded); 2. 60% FRW is huge when you don't use rapture, I like the fast movement speed; 3. Good pierce and big MO space means I don't have to make compromises with the rest of my gear to reach 100 all pierce.
PS. if you lag turn the ingame sounds off