the kinetic trauma is difficult to deal with, and not a lot can be done about that with so called hi power rifles.
ricochet is a problem for design. a round can ricochet the surface of the plate redirect and exit the edge striking upperlimbs, or head/neck area. this is mostly a consequence of hit from front. rear not so much but hitting someone nearby is very possible.
Yes, provided the trajectory of the round is such that it impacts the plate first.