Sorry, forgot to mention that Impulse is a better choice than Brainstorm, especially when you need top see certain cards quickly i.e. Pendrell Mists against creatures. When it comes down to how god your deck is against trinity green, the basic deck should deal with it quite well but you will need to see Pendrell Mists (probably multiples), and the all powerful Hecatomb this is where your sideboard becomes of the most importance. If these two decks are most popular in your area, and are the ones you are worried about playing against it is probably worth you to dedicating several sideboard slots to beating them. A suggestion of a possible sideboard is:
3 Magical Hack (good against Hecatomb, Boil, Choke etc.)
3 Dream Tides (good against weenie decks, especially good against trinity)
2 Hibernation (if trinity green is all over the place)
3 Annul (these work against Hecatomb and are also good for beating the Trix decks and the like)
2 Mana Web (this card is an absolute killer and is possibly worth a main deck slot)
2 Boomerang (I would run these to max out your boomerangs for against any rogue deck, because your main dck has little in the way of board control for anything except creatures. If someone gets an annoying artifact or enchantment (i.e. Stasis) down you only have two boomerangs in the main to deal with it
These are as usual just my thoughts and not gospel, a lot of the sideboard choices depend on your local environment (Where I live it would be like 4 DTides, 4 Dandan, 4 Annul, 3 MHack), and I thought about this board for about ten mins
. A good sideboard can make all the difference between winning a tournament and just doing well at one, someone said that to me once....... ahh yes Gizmo