Actually you can get your father to be the main rider of your SP even if your father doesn't have Class 2B. BUT provided you pay your bike in full cash and do not have any outstanding payments with any bike shops. Only in this case, you are able to get your father to be your main rider. My friend got a CBR400 under his name before he got his Class 2A, but he can do so as he paid in full for the CBR400.
As for insurance companies, they look at money more than they look at the licence. Even if (choy choy) your dad gets caught riding the SP without any licence, the insurance company also won't get into any form of trouble as any traffic offence you commit doesn't affect them.
Hope this can clear your doubts abit.