How do I attract merits?
post constructively, interact with users, join discussions, share useful information, etc... if you want merits, do those things. posting bounty reports won't get you any merits.
And I would really love to be a moderator here one day
I love the flexibility that the job gives.
How long will that take?
I don't know how long it'll take, but if you are consistent and continuously build up your reputation you'd probably become one. also, just because someone has a pretty good reputation does not mean they will become a moderator.