Alright, so Aeris and Aerith? Well, it was Aeris in my original copy (PAL) and I usually keep it that way, but then when it came to Kingdom Hearts it was Aerith, which I can't change, but oh well. Although I was confused at first, I quickly realized that it does not matter. The fact that it's two letters different doesn't make a difference to the story, gameplay, or overall effect in any way. Also, if you don't like this extremely insignificant error, change it. If you don't like the characters' names, the option is given to you to change them. Take this opportunity. You think it's Aeris? Leave it. You think it's Aerith? Make the switch. Doesn't change a smurfing thing. (Apart from the name.)