US Passport woe

[myriadofsins]

I've got my citizenship but haven't managed to get my UK passport yet. I'm going to Switzerland in a few weeks... which line do I get in when coming back and can I use my EU limit for bringing back lovely Swiss wine? Do I bring my citizenship certificate as proof or will they yell at me for not having a sticker in my passport?

I'm really confused and the Home Office has turned off the numbers I'm supposed to call and find out >_