Questions of language packs for W810i

Hi everybody,
I'm new here so do be easy on me.
Need your valuable advise.

I've just ordered a W810i from eBay and to my horror I've just found out that it does not support Chinese. I need both English and Chinese.

I have done a search but still couldn't get all my questions answered and most are quite vague. Thought some good souls here might show me the way.

1. The phone will come unlocked with English and Spanish. Will I be able to change it to both English and Simplified Chinese ?

2. Will I be able to type sms in Chinese after flashing or only able to read ? I need to be able to type in simplified Chinese and English.

3. Will English be still there or erased after installing Simplified Chinese?

4. Can someone please link me to the required Latest Programs (is it jdflasher ? ), Tutorial and Chinese Language pack download files.

5. Will I be able to download them as a new member?

6. Anything else I am ignorant of or have missed in order to perform a Language change ?

7. What is a CDA list?

I know this is quite a loadfull, do help. I'm totally lost here. A million thanks!