No it won't be the ISCV as something is telling it to do that, you are right it could be caused by a bad TPS calibration, does it do it all the time?

You can't unplug it permanently otherwise it won't run right as the ECU needs this info hence it being there in the first place.

It probably just needs adjusting but worst case scenario it will need a replacement which won't be expensive just requires fitting and plugging in.

Re the steering problem it could well be the 'Clock Springs' that are causing the problem.

Martin