2. Sorting threads by number of merits the OP has received.
Merits shouldn't determine how threads are sorted, I think the current system used to sort threads works fine based on how active the thread is(last comments).
A user with 10 merits can create a thread with more value than one with a thousand merit, thus why should the latters come/be sorted or placed first, this things have been thought through, that's why they have not been implemented.
And one can always bump their threads if necessary, this part is working very fine, I see no need for modification.