No, you can't.
If you go into a match with items on, YOU KNOW ABOUT THE ITEMS, AND YOU KNOW THAT THERE WILL BE A POSSIBILITY OF EXPLODING CRATES AND BOXES.
Never saw a single one in any of the E for All videos in Brawl, so that concern is gone. For realz, it should be a tournament option, because items like the beam sword, home-run bat, fan (throwing all of them), TEH BUMPER (best item ever b**ches!), Gooey Bomb, Proxy Mine, hell even the Smash Ball/Final Smash and Banana Peel can involve some strategy to it. I don't understand this "zomg! Items are about luck only" crap for Brawl. That was in Melee, this is Brawl. No one ever says in Halo it's cheap when certain items (weapons) respond in certain places. Items in Brawl (from what I cna tell) involve adapting to your enviornments, and giving you more options of attack, defense, timing, combos, and whatnot.
In other words, they all seem to have mutiple uses. TEH BUMPER is a combo machine, and a awsome edge guarder. The proxy mine is good for hiting opponents against things in a single hit, or for combos. the beam sword enhances your A moveset range (and probably power, but not too drastically), for throwing as a projectile, and can be mindgamed via are you going to smack them via Melee attack, or chuck it? Pitfall is like a GOOD version of Donkey Kong's fB, and can be used like a placed proxy mine in that sense.
Simply put, unskilled people won't have the advantage if we limit the used items to throwing items, mine-like weapons, and (physical) weapons (I'm very unsure on long range weaopns and guns), and we limit them to low or very low. Simply put, it's using your enviornments to youradvantage-like Advanced Techs, but diffrent, and in limited number. I've always wanted to see the diffrence of pros playing with items-to compare and contrast with them playing without items. In Melee, items sucked thanks to explosions. In Brawl, that needs to change. Hopefully everyone making and helping on Brawl realize a lot of the things with Melee's items were stupid, and continue to add some awsome items. If items are tournament legal-there needs to be minimal of them, definitely. No one wants the Super Spicy Curry, Hammer, bomb-ombs, or Golden Hammer=overopwered, stupid, and should die! XD