Steve didn't say much about trying to make the USA team at the Team Trials, so a single gear is fine. I flew a Flight Streak for years with a single gear and no real ill affects. Look back at some of the Soviet planes that had wheels on just the fuselage centerline and tip skids.
Well, I find takeoffs and landings to be much more pleasant with a two-wheel gear, although tip skids would go a long way toward making me feel good about one-wheel takeoffs. I also don't feel that a single-wheel gear gives me much chance to practice my takeoffs and landings in a realistic manner (never mind that in practice I fly mostly over a mix of grass and noxious weeds, which make that difficult as well).
This is what the rule book has to say about landing gear:
Any main landing gear or other appendages affixed to the model which, in the judges’ opinion, are unrealistic or impractical for use on full-size, man-carrying aircraft, will not be allowed.
I don't find single-wheel gear without tip skids to be realistic, so I would figure that any contest I entered with it would be a roll of the dice, however heavily loaded in my favor. I like to be on the right side of the rules (or at least be in a position to argue them over to the left of me), so I wouldn't want to show at a contest with a single-wheel gear.
I
would expect that any single-wheel (sans tip skid) plane that I flew in a contest would automatically give up at least ten points each on takeoff and landing for the loss of realism and smoothness.
So if Steven wants a plane to just fly -- sure, keep the stock single wheel and have fun with it. But if he's going at it to develop himself as a stunt pilot, I would highly recommend that he use a two-wheel gear, as well as a tall tail wheel to give it the right stance for a smooth takeoff.