I am looking at getting a sponsorship with Raleigh through my blog, since I went about 8,000 miles on my Port Townsend. That frame is about dead now, and they're looking at putting me on a Roper.

As far as I've heard, the wheels it comes with are the heavy part. That might mean they're stout enough for touring already; I suspect they are strong enough for touring, and I'm basing this assumption on the distance I went on the stock wheels on my port townsend. After 5,000 miles, they were about dead (you could see flanging around the nipples, they never actually failed or even busted a spoke), and I got some Mavic 719's and XT hubs. So, ride them till they die and then get new wheels.

The drivetrain is all Shimano 105, but the issue you're having with the rear derailleur might be solved by either going with a full housing, or at least getting the rear section of the derailleur cable housing sealed. Talk to your mechanic; this is an issue that isn't limited to the roper and should be an under-$20 fix one way or the other.

The part you may want to upgrade is the brakes for loaded touring. The Shimano disk brakes are not very strong, and if it's you plus your gear, you'll want good brakes. I think replacing just the front brake with an Avid BB7 is enough to get this bike ready to tour.

Honestly, though, raleigh has a habit of overbuilding their bikes in the steel commuter category so that they don't get complaints about durability. This bike looks good to go for loaded touring to me, and that's exactly what I'm gonna do on it too!