you don't need visa to get a sim card, just buy it off from the street, all you need is to register you card within a delay...

you can use renren or qq or weixin, or simply buy a vpn from hk or other countries to acess blocked websites

there are many packages for mobiles phones, have someone translate it when you are subscribing

Yes, you can get it off the street or off of taobao.

Chinese are willing to pay a lot of money to get "lucky" phone numbers. If you don't care for a lucky phone number, then you can get a GSM SIM card for almost free.. Adding money to the SIM card to get calls is a bit more complicated and I rely on my Chiense GF to do that, although you can go  to the China Mobile store and there are machines there that can add money to your phone number.

Just be aware, that although SIM cards are everywhere, not all shops have the tools to properly cut your SIM card if it isn't the right size.   My Motorola Razr takes the same tiny sized SIM cards as the iPhone and we had to go to a couple shops last year to find a place that could punch-out the SIM card down to size.  I think this year, the micro sized SIM cards are a lot more popular though so maybe it won't be a problem.

In China you can get SIM card without any ID proof and Address proof..also you have to pay different price for different number..what amaze me much that few months back i was in tanzania..in such a under developed country..they also need your ID and address proof to buy a SIM ...but dont know why in China they do not need..

Different off-the-street SIM cards have different payment/billings plan -- some are more for texting and other are more for voice calls.  The price off the street is minimal and you need nothing, save perhaps, a working mobile telephone.  You need not even register your number anymore these days.

It's easy to buy a SIM card here, if you have questions, you can call me, in China for the mobiles, generally we have two selections...