We've one talented guy among the VT ranks who uses a joy-pad (the analogue sticks), which I can't fathom at all...
I spent the first few months with GPL using a joystick, as I'd used that method for GPx for a few years, and picked it up instantly, getting a negative rank quite quickly, but it's far from natural. After around 3-4 months I bought a MOMO Force wheel, and I've gone from strength to strength since, only recently falling into a relatively low vein of form results wise, as others are improving around me.
Forget GPL offline - it's good to get used to the game, but you need to move online very quickly to make the most of it, and learn from others. No matter how good you are, you can always learn from watching others.