Yes you need to provide a copy of your registration form if you want to get the "extension" in China. There are no problems registering on a tourist visa at the local PSB, they tell you to do it on the immigration forms. Like i said earlier, so long as you've filled in the paper work correctly or gone to the PSB on time, they really don't care, it's that pass the buck mentality, they've done their small portion of their job to the letter that's all the matters!

Unless you're applying for a multi entry L visa with a year validity which i think it wouldn't hurt to have an itinerary of what you plan on doing to help the application, no you don't have to show anything. Not even an airline ticket or hotel booking anymore. This is all for UK passports tho! The extension for a UK passport in China is 160rmb a time, but for a US one i hear it's over 1000rmb. Something about the UK and China having a friendly relationship....or as i call it, Hong Kong!