1) Merit-sourcers do not have the right to hand out merit to voters in contest topics and derivative discussions. If a merit-sourcer wants to say "thank you" to his voter for the vote, then nothing prevents him from doing it via PM. The usage of their powers by meritsourcers for their own purposes is a dishonest game. If merit-sourcer violates this rule, he should be redtagged as "Voting manupulator".
Meriting everyone that qualifies to vote and voted is not bad. Merit earned can be given to any useful posts, but in this second case, it would be preferable if the merit is given after the contest has ended. It would have been more respected if you have PM icopress about this for suggestion and to include the rules in the next contest or post about it appropriately. No one is manipulating anything and not in the rules not to merit until after the contest.