Wow... I've been a lurker here but I had to register to respond to this thread. What you described is exactly what I had in FFXI :)
When FFXI launched in North America I didn't know anyone else picking it up, so I'd joined a large linkshell (100+ members) so I could meet some other players. There were 8 of us that ended up meshing really well, and we were always grouped up.
Between high school, university, work, and being a single parent, none of us had the ability to dedicate the hours necessary to reach the higher level content, but I think we probably had more fun than a lot of players who reached max level.
We'd fish, we'd hang out by the ferry and talk, we explored around, helped one another, crafted, and sometimes leveled ;) We had all agreed not to outlevel one another, so we spent a lot of time goofing around to avoid getting too far ahead. We did everything together, a real group. When we all took our first ride on the airship together... that still brings a smile to my face to this day. We were all blown away by the ride and the view.
Another memory that stands out is the time we'd made the run to all learn the bard job, and then afterward me and 2 of the other guys tried to start a band, singing at the same time with the different race voices. It did not sound very good, lol.
We never achieved a very high level, but playing with that group of new friends was the most enjoyable time spent in any of the MMO's I've played since Ultima Online. Every new experience was made that much better because it was fresh for each one of us, and we got to share that enthusiasm.
I really hope your casual community works out. It truly is the most rewarding way to approach a game like this. I'm going to keep an eye out to see what server you and the others end up :)