Throttle Body /EGR clean needed ?? - Mk 3 1.6tdci 2012

Have had car for 3 years and throughout that time it has:

a) when slowing down and dropping the clutch the revs don't drop immediately but flutter, then tail down. Stop start queues on motorway make this very irritating.

b) when cruising at a steady speed and lightly lifting foot on accelarator, the car often jolts, rather than just slowly slowing

c) running down the a hill with the foot off the accelerator there is a slight continuous judder/lack of smoothness (tricky to always be sure as suspension does feel any bumps)

I am a have a go novice. Based on the checking so far and googling I'm thinking my symptoms could be dirty throttle body and EGR, or one other or both not quite working ??? anyone agree theoretically ?

I have the free Forscan and a nice new battery. I've started using live data, but haven't captured an incident with the above symptoms yet. The Clutch and Accelerator sensors seem to do their job. The throttle does seem to close when I drop the clutch to change down gears. The MAF plot follows the revs well. The 2 wheel speed sensor plots match each other.

Having just worked out where the throttle body is, the plastic inlet pipe upstream on the EGR side, had oil on it (in the area between my fingers on the attached photo) . I cleaned it and there was more oil on it after a long drive. I can't see how this gets there ?

Haynes manual is no use on cleaning either, so I need to find more info/videos. But before I get carried away.........am I potentially barking up the right tree for my symptoms??