From what i have seen.
1st Penumbra can't have hands.
2nd if Penumbra will have hands,hands animations will be scripted to escape the awkwardness.
3rd perfect solution is to use scripted animations synchronized with mouse controls.
Thus making the reach pretty short(hands length),hands should have block points - You can move player's arm at it's limits.Hands could be controlled with left and right mouse buttons(left,right hand) pick the object with right mouse button(right hand), + add left hand if the object is too heavy to carry.
Small objects could be inspected when they are holded - press use button or 3rd mouse button(scroll button),then player will be able to see object with scrolling,or holding use button and interacting with it even further.
Well,should make use button and scroll button,it would be quite essential.
CoC made a nice of them,in cutscenes,real time,etc.When player clicks on door's knob real time animation starts and proceeds when mouse is holded and pulled.
One should be able to interact with items and doors with both hands.
In the end,the whole thing with hands should consist of animations,hands with block points and joints(hand can't go through things,it should block),animations synchronized with mouse controls.
For such a pretty cosmetic effect,its costs a lot more.
In advertisment it should say:
WE HAVE REAL HANDS IN DIS GAME!