Re: New cloverleaf owner
Revs holding at 2k before dropping sounds like an idle actuator problem to me. You can take it off and clean it with carb cleaner or similar, then lube it and stick it back in.
Straying to the side at speed, could be tracking or wishbone(s) but check all the tyres and pressures first. My experience with worn wishbones is that the car veers one way while accelerating, but the other way when braking or decelerating.
Temp at 40c, I'm certain this is a stuck open thermostat. You can check by starting the car up and feeling the temp of the pipes coming from the stat. The one that goes to the radiator should remain cool until the stat opens and then get hot rapidly. You'll probably find it heats gradually which is a sign of an open stat.
edit : hadn't seen Mave's post when I replied and it is possible that the stat is causing the high idle, although not sure if this would be the cause if the revs do drop back to normal after a few seconds, and then after presing the accelerator again they remain high again for a few seconds before dropping.