There's little reason not to wear a helmet.
In fact I would generally associate someone of higher skill who wears a helmet snowboarding cause I would see them rip through the terrain park and bust something way bigger than I could do. Till then some newb with a helmet comes along and you think he's like the rest but he just sucks, lol. But anyway, still seems like more of the serious freestylers wear helmets than not.
And if you consider the freeriding racers, they wear helmets. Consider the hardcore backcountry dudes, they wear helmets.
So yes, I would recommend wearing one and not listening to that other guy, especially at the level now where you can somewhat carve but are prone to harsh mistakes (catch an edge).
Although I never have worn one. I'm not sure if I ever really bashed my head. Can't seem to remember... wonder what they would imply.

No I've never got a concussion or anything but fell very hard many times and might've just been lucky.
As far as carving toe side, I can understand why it is harder than heel. Most people do heel first, some can't ever seem to feel as comfortable with toe side, one big reason probably that you are turned around and your back is more facing in the direction of movement (like how it is usually less comfortable to spin backside than frontside). But anyway, it really is just the opposite movements. Once I learned to carve, I realized a major reason that I caught so many edges and totally pwned myself (talking monster bruises on my knees, sore everywhere, but I was a kid then) as not lifting up my heels/toes.
So when you do a heel side now, it is like just standing on the ground and stepping back only on your heels so your toes lift up. Except with a snowboard on a hill, lifting up while being bound in lifts that side of the board higher than the hell side, and the downslope of the hill means you don't need to lift it as high as say on the ground. Same with toe side, step way forward, lifting your heels and having the weight on your toes. Again, on the hill bound to the board, even a little bit of pressure will keep that side up enough from catching an edge while your toe edge is carving into the snow. Got it?
