Photo manipulation - portraits

Having a bit of a crisis of conscience over photoshopping portraits.  I've recently done a load and many of the people involved (mainly the young girls) asked me to photoshop them.
I'm OK with doing a bit of skin smoothing etc, but where would you draw the line?
This is a list of the things I would normally consider doing to an image: -

• Skin smoothing
• Spot/blemish removal
• Brightening of the eyes
• Darkening of the lashes
• Colour matching of teeth
• Removal of stray hairs
• un-closing of eyes (usually as a clone from another similar image)
• removal of bright/shiny areas

What I am not so sure about is when I am asked to change the overall shape or add to/remove from the image: -

• reduce the number of chins
• give someone more/less hair,
• make the eyes bigger
• plump the lips
• "make me look like a supermodel"
• make people thinner/broader/taller/shorter

What do you normally do, and where would you draw the line?