I find all the chatter about the "Should he? Shouldn't he?" interesting. My advice is you won't know unless you try it! There is no shame in trying, and I say go for it. Lauren went through a similar scenario back in 1993 after fainting at the USAT AG Champs (Leon's). While she was winning the local races, she was unsure she had the talent to be competitive in the deeper pro fields. Racing with the professionals escalated her racing to a new level.
My advice would be to treat the first few seasons in the elite ranks as an opportunity for learning, especially at such a young age (to a Master's athlete like me, anyway).
Do not measure success based on prize money earned, but on continued personal improvement. Don't assume you need to be fully (or even partially) sponsored to attempt this - sometimes the effort to chase sponsorship distracts one from the main goal which is racing fast.
And be prepared for a new level of bureaucracy (drug testing, pre-race meetings, the stagger rule) that is not a part of age-group racing. -TJ