Although, this merit system would prevent many spammers and account farmers on our Bitcointalk, but I would like to give suggestions to make it better-
1. Decrease the merit of people based on negative trust from trusted accounts.
Both are for different purposes. Merit is to judge the quality of posts being made by the member. Trust is more like the credibility. Mixing the two is not a good idea.
2. Increase the merit of people based on positive trust they get.
Same as above.
3. Instead of giving all the users (initial) merit based on ranks, give merit based on activity.
This might have been more fair and now a decision has already been made. Many new members made complains about this but I do not think that the decision is going to be reversed. At such, all we can do is adapt to the new system. We should give the new system some time before making any changes. I think we can expect requirements like having fixed number of merits in a year to maintain a level.