Yes, we do have to be careful so as not to spoil anyone's surprise. I know that at least one person here just recently finished the 6th book. We discussed the BIG surprise out of that book in PM's instead of in the thread.
Once we get partners, you can decide if you want to craft for one fave character or two or whatever you two are comfortable with. We just want to make the crafting specific to characters and not houses. Favorite house is a separate swap that we'll be doing down the line - was it 3rd on the list?