I can't answer as to the ADHD, but I can answer as to the tax rate.
For Alamance County it is .58 and for Mebane City it is .5, giving you a total tax rate of 1.08. For Orange County it is .95 plus Mebane City of .5 gives you 1.45 for the Orange side. So your total tax on a $250K house on the Alamance side would be $2700 and on the Orange side it would be $3625 per year. You could also have a Mebane address, but be outside the city limits, in which case your tax would be much lower because you would only have county taxes + fire without the city taxes.
Tax Rates - Alamance-nc.com
Orange County NC Revenue Department
As for schools, we preferred to stay on the Orange side because of the schools, but many people seem happy enough with the Alamance schools too. You can look up their scores on
NC School Report Cards (http://www.ncreportcard.com/src/ - broken link)