TVC uses on fighters

most of the discussions (and fights) about TVC on fighters tends on focus on airshow type moves like cobra, firing tvc missiles at odd angles by snap-turning the plane etc etc. I want to know if the real combat uses are

* manouver the plane better at high altitudes like > 45kft where air is thin? do
normal fighters move sluggishly at those heights? does a high T:W ratio also help up in those rarefied heights?

* enable large planes like raptor and flanker to mix it up closely with nimble small fighters like gripen and hold those tight turns better?

* orthogonal moves to enhance chances of AAM/SAM evasion?

* easier takeoff from short airstrips with steeper climbout?

what exactly was the TVC added on Raptor for ? I figure same reason should apply to flankermki.
:confused: