Ive had this problem on all cars over 1.8 litre. I spoke with Volkswagen and audi specialists and the concensus was that its a thing called overrun. Its almost like an automatic choke....so for the first few miles in the morning the car runs in overrun mode until its warmed up....this basically makes the engine breaking more so if you take the foot off, makes it feel sluggish, and then suddenly repsonsive if you put you foot down....and so forth. Pritty much all what you guys have said already. It affects alot of cars new and old...all with automatic choke/fuel injected.
The clutch issue where sometimes u need more gas than other times im experiencing as well and im not sure about this either...i assume its just somethnig we have to get used to..