If you have a complete replacement body four limbs and skull and torso. Do your original stats in agi, str and bod count for anything?

If I don’t take a cyber skull what does that effect I find it difficult to have it take into account for agi or str other then head butt attacks.

How much armour do I have if I have 2 armour on every limb but a normal head ?

First of all, although SR4 fixed a few of the older cyberlimbs issue, they haven't fied everything. The strategy in SR4 for cyberlimbs was: "If we're not sure, don't talk about it". So, there are only "guidelines" in SR4, so I will answer based on my interpretation of those guidelines:

1) Body is still used for test about disease and pathogen resistance, though, so watch out for that one. Rest is scraped.

2) Yeah, stats for skulls are dumb, aside for armour. You may ignore them if you wish.

3) I, and many others, do not count the head when averaging armour. This is up to you. If you don't count the head, add all armour points bought for all your limbs, and divide by 5. If you do count the head, divide by 6. So in your example, assuming we don't count the head, you have 2 regular points of armour.

As he said, if you have a full cyber-body, the only natural stat of the three that ever counts for anything is body.

I personally just use the Agility, body, and strength of the torso for the odd situation in which stats for the head specificly would matter.

I average everything but the head, and treat any armor on the head as a helmet, because that is the only interpretation that is consistant with the rest of the rules. None of the armor's in the book take head protection for granted. Even the full body armor has a separate helmet that gives a separate bonus. Thus, it would be rediculous to average the armor on the head in with everything else.