Interesting Idea, some Randomized movement to the Enemies or let them Follow Waypoints would help already a lot to give the game more Depth and Challenge.
The Collisions and Clipping are insane same as this weird Mouse thing going on.
Also you work with a Dynamic Rigidbody, when you collide with something the Characters starts Spinning because he has velocity on the Rotation. You need to Reset that after a Collision or set the Rigidbody to Kinematic so this wont happen.
Make the Colliders of the Objects bigger so the Player cannot clip inside would be the first approach to deal with Clippings. For more Experienced work with Cinemachine and turn the Camera based on the "Clipping" Cinemachine provides already alot useful inbuild Stuff to prevent Clipping.
Anyway Cool Idea, Solid Work keep going!