TPS issue, but only when its in the idle position...?
You have tried quite a few things and seem fairly competent with the solutions you are trying. If you are continuing to try this DIY, maybe get the emissions checked and see what the car is doing fueling wise at idle - rich or lean. From your symptoms Id suggest rich.
If the fault goes under load, then like you have already said this points to an O2 sensor - which you have changed. Has the car been code read since you changed the sensor? The issue may be a poor connection in the loom.
TBH this sounds like and electrical sensor problem, its just finding the issue on these newer cars...
Idle control valve, if sticking will reduce the air to the engine at tickover, and will give a slow idle, it shouldnt drop a pot and run rich if the idle control valve is at fault.