Recovery time after wounds

I'm not sure that the shield blow would be very likely to dislocate the shoulder, but the fall certainly could.

1) The spear can go right through without permanent damage. It depends on the thickness of the spear and where it goes. He could die within minutes if it hit the artery.

2) A few minutes to never. Again depends on the wound. With medieval or renaissance level surgery he could well develop sepsis and have to lose the leg or die. In fact it would be pretty likely.

3) Dislocations are not generally a serious long-term problem. Most of the time, you pop it back in and it'll just be a little sore for a while, unless it's replaced in the socket incorrectly.

As a general rule wooden spear carries a greater likelihood of leaving splinters and other debris in the wound, which in turn would increase the chance of infection or abscess formation. So if you wanted to drag out the poor sod's suffering, that would be one way. Given the setting, it's a safe bet he'd develop some kind of infection, and without medicine it'll spread and cause him major problems.

Healing time would depend on the severity of the wound, and so would the character's ability to walk. If nerves have been severed, or ligaments and tendons badly damaged, he might walk with a permanent limp or perhaps never use that leg again. You'd be looking at quite a substantial wound to cause that sort of damage.

war is a well oiled machine

Soldiers oiled their weapons. People don't remember that because it's been well over a century since spears were the dominant weapon. Also most people don't take proper care of their shovels.

Shovels, really? What's the point?

The point is care of wooden tools.

Properly cared for, the spear will not give of itself. It will not leave splinters. If it's splintering, then it is weilded by a hack

Primitive wooden spears were generally 'fire hardened' - the tips would then not splinter, and hold their point longer.