I hope you don't mind but I saw what you said about aging spans and there's a simlogical 'hack' that lets you easily edit the age spans to your liking.
http://www.simlogical.com/sl/Sims2Pages/Sims2_Aging.htm
It's called 'Age Group Tweak' and all you have to do is edit some values then put the file in your downloads,and you have your own set of age spans!