I think what you have there is the basic STX-spec rigid, which sold for £500, but there was an 8-speed 'LX' option for an extra £100, or you could specify a choice of forks. e.g., STX with Indy XC would cost £670, or LX with Marzocchi Z2 would cost £940.
I expect you have a 7-speed Alivio hub, which you may feel doesn't quite live up to the nice Mavic 238 rims. Having said that, my commuter Orange C16R has guess what STX 7-speed shifters, just like yours, and Merlin-built Alivio hubs in 230 rims, and that has the best, most positive gear change of any bike I've ever owned. Now loaned to a friend, and he says the same. If you want to throw your wheels away, please throw them in my direction.
I don't see why you shouldn't run it as single-speed without removing the cable stops. If after a while you are sure you want to keep it that way, go ahead and remove the stops. But I just suggest that you could come to regret removing the stops as part of an experiment.
Incidentally, I just looked at your Eldridge Grade, and I notice that is much bigger. If I'm right and the Voodoo is a size 17.25 (centre of bb to top of seat tube), it should have a c-c top tube of 55cm(?), 'effective' top tube of 22.5" and according to the catalogue it is designed for a riders of 5-5 to 5-9.