TPS testing info:
MK3 TSRM On-Line
The alignment info is two pages later, test it first the TPS is a wear component.
Why do people have to keep screwing with the "idle screw"? It's a modern car! The idle is computer controlled! So unless you've already moved it, odds are it's right where it needs to be... which in this case, yes, I know, you've moved it.