I'm not such a fan of the staggered licence system. Despite many attempts by different bodies to prove it, including the Governments TRRL, there is no link between horsepower and the likelihood if crashing a motorbike. After all, if its so brilliant rten why wasnt it applied ro new car drivers?
As a motorbicyclistist of 34 years to standing myself, I know first hand that you're far, far safer on any middleweight sports bike at 70mph, with brakes and handling to spare, the than you would be on a CG125, where you're right at the ragged edge of handling, on skinny bakelite wheels with very limited grip, and well beyond the ability of the brakes to help you if you get into trouble.
Riding across the country to get back to barracks I was far, far safer at 18 years old on my GSXR1100 than I was the week before on my 30bhp KMX200. 70 is 70, 30 is 30, 100 is 100, regardless of the engine beneath you - it's how and where you decide to do those speeds that matters, and the 33 BHP limit is zero impediment to that.
Being a tit is the problem. You can still be a tit on an estate road oitside a school at 100mph with 33bhp. The limited power in no way makes you immune to being a prat, and in no way negates any of the laws of physics when you muff it up.