Can I renew my NON-O visa 2 weeks early?

Seeing as you can't ever renew a visa, OR an extension of stay I will go with the premise that you want to go to the immigration office and apply for a new yearly extension. 😛

You can do that at most offices when you have 30 days or less left on your current stamp.

You don't lose any time going early because they add the new extension to your existing stamp expiration date

Yes you can apply for a new extension of stay between 30-45 days early, depending on which office you use.