I am an alt-a-Holic and I enjoy the various type of races and looks I get bored if I just stick to 1 character.Though it is annoying to not be able to mail items to my other characters there are a few ways round this:-

Use of FC bank ,sell items on the market at a silly price and then switch to other character to buy it,this is easy way to send gil to other characters and items,crystals this is the 2 methods I use.

But I wish SE would let us use the mail between characters just for your account and not having to be online.