Please leave your questions open for all.
KARMA has different definitions = It may simply mean action = Reaction to action = "What goes around comes around" = Actions of a life time that determine the fate = Actions in life that determine the next rebirth or new JANAM = They think that evil actions can cause a Hindu or Buddhist to be born as a mouse = Good actions can cause him to be born as a Brahman or Raja/Rani = And so on.
As we have seen before, Reincarnation is the non-Quranic cyclical concept of life. According to the Quran, life is evolving to higher forms, a linear ascent ('aqabah).
11:56 Indeed, my Lord is on the Straight Path.
See 90:11-20 "Aqabah".
My answer may still be incomplete.