The first three poses you list are not particularly relevant for the knee joint as it is a hinge joint (like a door) and only goes in two directions. The damage that is done to the knee in those poses is done because a) the student approaches posture aggressively and/or b) there is not enough opening in the hips and therefore the action of the pose must go into the next joint in line, which happens to be the knee.
It is relevant, however, to reference Supta Virasana, though in that posture the shin bone is on the floor but the kneecap itself is not. To further complicate the comparison many students lift the pelvis and tuck it in order to come into the pose. And while that allows the student a sense of doing and accomplishment it is not a legitimate indicator of the opening in the quadriceps.
If the weight on the knee cap in Vanarasana (lunge) is unbearable consider folding the mat laterally or using a blanket/foam pad under it for comfort. Unless there’s a pre-existing injury I’m not aware of any danger in resting the kneecap on the floor.
In the meantime it is balance in the hips which maintain the integrity of the knee. A student that is very open in external rotation but not so in internal, or one that can do Supta Virasana (or Eka Pada Supta Virasana) but cannot catch the big toes while keeping the leg straight in Supta Padangusthasana these students do not have a balanced hip complex.
Have your teacher look at and assess where YOU need work in six of the eight actions of the hip and work those accordingly in your home practice.