Hi
you lose nothing by making an appeal, although you have missed the deadline. It may still be possible to make an out of time appeal if you can show good grounds. Normally you have ten working days after receipt by you or your representative; the failings, if any, by your previous solicitor are considered to be down to the applicant, as it is up to the applicant to choose a good rep. Still, you can try for an appeal, there's nothing to lose, and no reason why it should adversely affect any future application.
You say yourself that his case is weak, but be guided by a solicitor with asylum experience.
As for the comments and tone of the Reasons for Refusal Letter, this is absolutely typical, and nothing to be unduly worried about. Such letters are typically drafted in the most negative possible terms, putting everything in the worst possible light. The court is much more likely to be even-handed, but still won't grant asylum if there is not a good case in law for it.
In practice, few failed applicants are removed to China; it may be possible for him to remain and hope for eventual regularisation. On the other hand, voluntary return to China, and return here with a spouse visa may well be the best option. He can go to the Chinese embassy to get a passport made, or he could contact
http://www.iomlondon.org for assistance and impartial advice.
Make sure that you have lots of evidence of your relationship, finances, etc, and get him to sort out his English! Check out some other threads here about similar situations.
The Refused are coming day-by-day nearer to freedom.