It seems your sources didn't give you the correct information. First of all, there are generally two methods for obtaining the end result you desire. You can arrive in China with your ordinary "L" tourist visa and then go through the process of obtaining your work-related legalities or you can arrive directly on a "Z" work visa.

If your company is not handling this process for you, I would be wary as it is likely to be either a small school (English teachers) or a very small company that, in most cases, is not even legally allowed to hire expat staff. No matter what you do, you'll never get the necessary documentation / authorizations to work legally. Another possibility is that the company does not meet the conditions required to allow in-country conversion of an "L" visa into a "Z" visa and you will be forced to collect a variety of documents and must then go out of China to re-apply for the necessary "Z" work visa.

Unless you are a gambler, the best route is to have the company provide you with the necessary documentation so that you may obtain a "Z" visa from the Chinese consulate in your country of departure prior to coming to China.

If you arrive in China on a "Z" visa, the process to obtain your residence permit is quite simple and can take about a week. If you arrive on an "L" visa, your process is something like this:

1. Health Certificate
· Passport
· A copy of your passport
· 2 passport photos
· Original and copy of your company's current business license

2. Work Permit (Red Book) from the Labor Bureau
· The foreign Work Application Form with company stamp
· A copy of the business license & original
· Resume
· Work contract
· Qualifications Proof (a copy of personal highest degree, Skill certificate)
· Passport and a copy of your passport
· Possible legalization of degrees and certification and then official translation into Chinese (sometimes required, sometimes not)

3. Residence Permit* from the Division of Exit & Entry Administration Dept. of Public Security of Beijng.
· Temporary residence registration
· Work permit
· Health certificate
· 2 passport photos
· A copy of the business license & original
· Passport and a copy of passport
· Application Form with company stamp
· Fee: Depends on nationality

* It is not a green book. That has been eliminated. It is a sticker placed in your passport which seems like a visa, but upon closer inspection it is not.

Leaving the country isn't difficult, but it will cost you approximately $500 in airfares, accomodation costs and related expenses for a short trip to Hong Kong.

Yes, the residence permit is tied to a specific address but you can easily modify your address should you move. On a related note, the residence permit is tied to one specific employer and it is very complicated to change should you leave your first employer and decide to work for another one.

If you obtained a "Z" visa / residence permit to work for Company A, it is not valid once you leave Company A. There is a process for legally changing employers and transferring your residence permit under your new employer, but it requires a letter of release from Company A and obtaining a new work permit before the PSB will approve it, if at all.

Going to Hong Kong is what most people would do as it is not only the cheapest, but where you may have the least amount of problems at the visa office.