First Person Controller Physics

Alright, so I have noticed if you have terrain which is too steep to walk up (ie: vertical), if you press spacebar and forward, you can continuously jump and would be able to reach the top, this is very inaccurate physics, as there is little support force to hold up the user, without even considering balance.

How can I go about solving this?

Check out this answer: Slope Limitation for Rigidbody Conundrum - Questions & Answers - Unity Discussions

Basically you want to cast a ray downward from your character, compare the normal of the raycast hit against the world up vector, and not move if the result is below a certain threshold.

You need to create physics joints for arms legs fingers and drive them, really complicated though.
There is a ragdol tutorial in unity: