Detailed questions about extending an L (tourist) visa

1. 3-month L tourist visa means that you shall enter China no later than 3 months from the date of issue, otherwise the visa will be expired. It doesn't mean that you can stay in China for 3 months. A single entry L visa is generally valid for 3 months, permits 30 days stay duration. The stay duration is counted from the date of entry. If L visa is extended twice, 30 days stay duration per entry for extension, you can stay in China for maximum 90 days.

2.
a) you need to go to the local Exit-Entry Administrative Office of Public Security Bureau to apply for visa extension.
b) the requirements for visa extension: your passport, the copy of China L visa on your passport, copy of entry record, fill the visa application form, one photo, the accommodation sheet issued by a hotel or a police station, bank statement (maybe you will be asked to open an account in Bank of China and deposit at least US$ 5000 into the account)
c) the police officer will judge it by himself, if he feels that you really needs to stay in China for more days, he will issue a visa extension for you.
d) it costs RMB 160
e) it doesn't require you to leave the country if you get an extension
f) you need to apply for a visa extension 5 days before the expiration of the first visa, it takes about 1 week for processing.
g) the extension is usually 30 days stay duration

3. yes, you can leave Mainland China to go to Hong Kong or Vladivostok in order to get a new visa and return to China once the original visa and 2 extensions are up.

I would like to thank HELPER for thoroughly answering my previous visa-related questions.
I would like to clarify some details about extending an L visa.

1. Could you tell me the Chinese term for the local "Exit-Entry Administrative Office of Public Security Bureau," and do you know how I would find it? I remember that last time in China there were no phone books.
2. As for the accommodation record, I will not be staying in hotels; I will either be staying with friends of friends or will try to rent an apartment. Do you know what information/proof I would have to bring to the police station? Do you know the name of the department I would be looking for or how I would find it?
3. For the "entry record," I don't remember getting extra documentation last time I went to China; is that a special form I have to ask for at Customs? If so, do you know the Chinese name for it?
4. For the bank account, I am planning to open an account with an international bank with branches in China, such as HSBC. Do you know if that would suffice?

Thank you again so much for answering my questions.