As I’ve mentioned before on SDMB, I think Willow’s problem is a predilection for looking for shortcuts - shortcuts to get out of an argument, shortcuts to feeling better after finding out that she pulled Buffy out of heaven (just erase Buffy’s memory of heaven!), shortcuts to getting out of feeling guilty for kissing Xander (offer to sleep with Oz, cast a “delusting spell” on herself and Xander), shortcuts to feeling better after endangering all her friends (cookies!). Magic just makes this weakness more dangerous, but it’s there without the magic.