It diesn't get any better after 50, I'm doing the archive missions at the moment, and I forgot how fearkin' long Chapter 2 is!!
There are other options for money, Pandora's Box, Datamining etc.
A good iTunes playlist and switiching your brain off is one good way of getting a lot of xp without realising I have found. There are Archive Missions to catch up on the story, but there is also the 'Contact' missions, certain NPCs around the city give a series of missions with allow you to learn a bit more about them and their influence on the city.
And yes, someone to chat to in /team and /faction chat really helps.
A playlist of music or radio is a must.
Sometimes I'm on our Ventrilo server, just to kill time while doing missions.
Mostly what they said, chatter in team/crew/faction. Take some mission buddies along, that helps too. (If available)
I've done two 50's and am working on my third. I just put some music on and just burn on with the missions
How did you lvl 50s overcome the mission grinding blues? At the moment I am lvl 12 and have purchased all of the archive mission packs to catch up with the story, as well as offer me some deviation from the monotany of the standard missions. Is there another way to break the cycle? Any help would be appreciated.