Not sure Bechuanaland/Botswana contributed much to the British empire, it didnt cost much but perhaps could have been traded for something more profitable.
Iraq was not very profitable in itself but rather as a strategic holding. If conditions whereby the seizure of lots of land was not crucial and India could be protected it would mean that unprofitable northern land could be left.
Not going into Afghanistan at all would have been an improvment, even if russia had gained the entire country they would have been drawn into a hell hole and were unlikely to have previaled or built up sufficiently to threaten India.