This laptop I'm using now does not have Chinese input installed so I have to type in English.
I'm not an expert in immigration issues. I just feel, through my experience, that the best strategy is to be honest and straight. I'm not saying that you tell 100% truth but at least you don't want to be looked suspicious.
Since you already have record being rejected for issuing Visa, it probably won't be smooth this time unless you are very convincing. That said, a trip to Seattle by yourself during winter is NOT a very convincing story. You might want to seek alternatives, such as joining some travel package hosted by some travel agency. Your story has to at least convince yourself.
I don't have MSN. You probably need to see advises from some real experts in this area. I can only give you generic suggestions based on my own experience, which may not be that helpful. If you wish you could Email me