Botox affects the muscles, not typically the sensory nerves. Numbness would be an unusual side effect and may not be related at all. Return to your injector for more specific treatment.
As long as your ophthalmic surgeon approves of the botox injections for the crow's feet, I can't think of a reason that it would be contraindicated. Your ophthalmic surgeon is probably familiar with the uses of Botox for cosmetic reasons and might want to discuss the plan with your...
As sinus headaches are caused by negative pressure causing the bony layers of the sinuses to be pressed in and the nerve endings transmit this force as pain, Botox which lessens muscle contraction would not be expected to minimize sinus headaches.