Hitboxes and Eye Level Cut-Off

There have recently been multiple amount of bug reports regarding hitboxes, especially being hit through walls. Some of them may not even be bugs, but something completely intentional in the game's coding.  For both scenarios, here's my thoughts:

An Example of the Situation

When a player (for example) is up against an inward corner of two blocks, their bounding box would be extended outwards to the corner on the other side of the two blocks.

This has been abused during PvP, as the people who know this would shoot that player when they are in that spot, leaving those who don't know completely clueless on what had just happened to them.

Hitbox / Eye Level Cut-Off

The way this could be prevented is having a player's (or any other entity's) hitbox being cut off when against a wall, almost like slicing a cube out of a cubic cake.  With this, it could get around being "hit through walls" in the first place.

The Eye Level could also be cut off when looking at a block.  This would help with certain mobs with a high amount of reach being able to hit players through one-block walls, such as the Iron Golem.  It would also prevent hacked clients from doing a similar thing.

With this kind of concept, it would prevent multiple problems that come with it, as well as related "bug reports".