Subaru Repair: 2004 Outback 3.0 L automatic, throttle position sensor, freeway speeds

Question
Three annoying issues with this car:  1)  It takes a while to shift from reverse to first.  If we are not careful (patient), the shift will occur after the motor revs a bit causing a pretty abrupt shift.  2)  Cruising at freeway speeds, if you step on the gas, the first response is a stutter before power flows smoothly.  Very brief, kind of like a head bob doll.  3)  Sometimes dies after starting when cold, or continues running but just doesn't make power when the throttle is depressed.

These issues we can live with but should we need to?  The warranty is about up and the dealer has provided no help when these problems have been described.  They have tried updating the ECU and "decarbonizing" whatever that is.  They suggest using only premium fuel as a solution.  (Doesn't make a difference.)

Answer
There is an updated Throttle position sensor, common problem with the H6 found in your LL Bean.

Has than been done yet?

Also for the dyeing it could be a ISC issue (Idle Speed Control)

Not much I can do with out seeing the car for myself other than give you the typical or usual suspects.