As far as the TB, before you pull it, take the pcv port and plug it off at the manifold, then pinch off the IAC tube with a pair of needlenose pliers. If the idle still doesn't change, AND you've checked the other vacuum ports for leakage, then pull the TB.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black