I would like to try to answer your questions in my poor English. If there is anything that is confusing you, please feel free to ask.
First of all, as far as politics is concerned, I think the most common political problem for most foreigners is not knowing that Taiwan, Hong Kong, Macao and Tibet belong to China. Keep this in mind and you can avoid offending us in most cases.
And then my answer to those questions:
About D&D (关于D＆D)
1. How big is the D&D player community? How big is the TRPG player community in China?
1. D＆D玩家社区有多大？ TRPG玩家社区在中国有多大
When DND was the most popular in China, we had dozens of BBS/forum about it, which I think represents at least 10,000 or even more than 100,000 people playing the game. But now, including this, there are no more than three active DND BBS players I know, and the DND player community is probably only a few thousand.
The TRPG player community in China I think is no more than 50,000.
2. How popular is Dungeons & Dragons in China? Is it the most popular TRPG or are there other TRPGs that are more popular than D&D?
DND is a very minority game in China, and its number of players has been mentioned in the previous question. I think the COC may be slightly more popular than the DND, but either way, they are among the most popular TRPG in China.
3. Can you list the popular TRPGs in order of their popularity?
The TRPGS that appear in “http://www.goddessfantasy.net/bbs/index.php?board=44.0” are all the TRPGS that have been watched in China, but I am pessimistic that they have such a small audience that they are not "popular" and their players are not enough to form a "community"
4. I see that unofficial translations of D&D 5e has been released. Have people started playing D&D 5e or are they still playing previous versions of D&D or Pathfinder?
4. 我看到D＆D 5e的非官方翻译已经发布。有人开始玩D＆D 5e还是他们还在玩以前版本的D＆D或Pathfinder？
We have quite a few people here playing 5e. In fact, I think the 5e is now the most dynamic and fastest-growing version of DND in China.
5. D&D 3E/3.5E was translated into Chinese. Was it popular?
5. D＆D 3E / 3.5E被翻译成中文。它很受欢迎吗？
Yes. This version of the rules is the earliest complete DND Chinese rule in China, and also has the most unofficial translation. So it has the most players - but I think the 5e will come later one day.
6. Has the release of D&D 5E the English (2014) or the translated version created a sharp increase in the number of D&D players?
6. D＆D 5E的英文（2014）或翻译版本的发布是否使D＆D播放器的数量急剧增加？
I don't think the increase is much, but it does bring a lot of new players to DND.
7. Do you think that an official release of the translated D&D 5e book will increase the number of D&D players?
I don't think that would be very helpful. Official running partys, campaign contests, and so on -- like those at GenCon -- are what we need.
8. Will people buy the official translated D&D 5e book if it is released in China? Even if the pirated copies exist?
9. Considering the popularity of Magic the Gathering, Do you think Magic the Gathering players will try D&D when the MTG setting, “Guild Master's Guide to Ravnica” is released?
9.考虑到Magic the Gathering的受欢迎程度，你认为当MTG设置“Ravnica公会指南”发布时，Magic the Gathering玩家会尝试D＆D吗？
I think so. But I'm still pessimistic.
10. Do you think that D&D will ever become popular in China?
Of course. But to get there, it needs a better, more powerful medium - VR, for example.
11. Do you think that D&D will have a better chance of becoming even more popular if it releases a World of Warcraft setting or a Wuxia setting?
World of warcraft? NO. Wuxia ? Maybe.
12. Are there any locally made Chinese TRPGs?
Very few, but yes.
About Chinese Players (关于中国球员)
1b. Where do Chinese players like to play? In face to face meet up? Online? Or by BBS or email?
Most are online, via qq, a social network similar to Skype, or via IRC. The second is face to face. Almost no one USES BBS or email anymore.
2b. What is the biggest problem Chinese players face when arranging a play session? Long work hours? Traffic? No place to play?
All the problems you mentioned are deeply troubling us. But the worst of them, I think, is the lack of free time.
3b. Where do Chinese players get their role playing inspiration from? Lord of the Rings, World of Warcraft, Japanese animation, Wuxia films or others?
Just like you said.
4b. Are there famous Chinese TRPG play group like America’s Critical Role? If there aren’t any popular play groups, how does D&D get popularised?
We have a lot of TRPG groups, but few of them are famous -- as far as I know, none as popular as the Critical Role. DND mostly appeals to new players through word of mouth between friends、DND vulgar novels serialized on the website by laymen who majority know little about DND for money、Tracing the origins (which we especially like to) of RPG games in game media.
5b. Do Chinese players play home-brew D&D games or do they play Adventurers League games?
Both. But the latter is more minority.
6b. Do you think Chinese players play differently compared to international D&D players? Do they like combat more than role playing or is it the other way around?
I don't think we are much different from them. I think for most people, they like role-playing when it comes to porn and like fighting the rest of the time.
7b. I have a Chinese Australian friend who says that Chinese are very competitive and Chinese prefer games where they can win instead of collaborative storytelling games. Is that true?
We do prefer to win. I think this is the result of too much stress in our lives.
8b. Where do most Chinese D&D and TRPG players come from? Larger cities like Beijing & Shanghai? Cities like Shenzen which is closer to Hong Kong? Or they come from everywhere?
Across the country. But big cities, as well as Taiwan and Hong Kong, have more players.
About Censorship (关于审查)
1c. Do you think that D&D would be censored or banned by the Chinese government if it’s released in China?
Don't. We have officially sold DND3.5.
2c. In America in the 1980s, there was a satanic panic. Religious groups think that D&D was dangerous. Do you think the same thing will happen in China?
Will be. In fact, we're facing this horror, but it's not about TRPG, it's about video games. Search “杨永信” for more information. If one day TRPG becomes as popular as video games, there will surely be similar horrors to befall us.
3c. I heard that skeletons and ghosts are censored in World of Warcraft. Do you think that undead monsters in D&D will be censored?