Gemstone is a long haul game, and it's the people who make it different and worth committing the time to. It's very different from any other game out there, so your learning curve is going to be huge. There are lots of people on lnet on the ;help channel who'll help you out with answers to questions. I've heard of people going from 0-100 in just under a year. The fastest I've known anyone to do it was about 2 1/2 years of regular play (20-30 hours/week). You can buy a capped character, but quite honestly, you'll get a lot more out of the game if you play one up through the levels and experience all of the different parts of the game world. There isn't as much RP as there used to be, but you can still find it if you're willing to put the time into it. We don't have raids, but the GMs will frequently run storylines for the different cities. Sometimes they're done just for fun and can wrap up within a few weeks, sometimes they're part of a larger story arc that can take months to play out and can span across a large area of the world (stock up on deeds and expect to die a lot during these). As far as gear, I know people who have hit cap in basic 4x gear. The uber gear is nice, but it's not necessary to enjoy the game or be involved in everything.
"Can take down a construct, can't kill a dire bear. Bloody hell, woman."