Hello,
You are free to request server merges as much as you'd like. The server merges will occur once Oasis feels that they are necessary, which is not at the same point as when the player base feels that they are necessary, unfortunately. The line, "server merges will take place once every two weeks" is in error and is meant to say "no more than once ever two weeks".
Server merges will be announced in the News forum when they are happening. Asking friends about them won't really help, because your friends won't really know about merges ahead of time. The only way to find out about a merge is to check the News forum for the announcement. That's really the only way to find out about a merge announcement.
I hope this helps, and sorry for the confusion!

It really depends on how long it takes for the problem to reach a critical mass. If there are enough server merge requests and the servers in question fulfill the other requirements for a merge, then it could be quite quick. If not, then it might not ever happen. We have servers that have never seen a merge. There's really no way to be certain, and those policies have never been made public. Unfortunately, we just have to check the News forum weekly for updates.