I think the use of heavy armour has its place and needs to be used properly during operations or defence. The capability is proven and available; use it. And as for the thoughts of not sending them to prevent the locals of thinking we are an occupation forces is naive and well quite a few years to late. They had those thoughts the moment we put boots of any kind on the ground.
Here's a few great lesson's learned articles on the use of tanks in Afghanistan and their use in COIN.
http://www.defpro.com/daily/details/273/
http://www.army.forces.gc.ca/caj/documents/vol_11/iss_2/CAJ_Vol11.2_05_e.pdf
http://www.army.forces.gc.ca/caj/documents/vol_10/iss_4/CAJ_vol10.4_03_e.pdf
And here is a British article on the deployment of the USMC Abram's that discusses the Canadian and Danish Leo's.
http://www.thinkdefence.co.uk/2010/11/usmc-panzers-to-afghanistan/
Here's a few great lesson's learned articles on the use of tanks in Afghanistan and their use in COIN.
http://www.defpro.com/daily/details/273/
http://www.army.forces.gc.ca/caj/documents/vol_11/iss_2/CAJ_Vol11.2_05_e.pdf
http://www.army.forces.gc.ca/caj/documents/vol_10/iss_4/CAJ_vol10.4_03_e.pdf
And here is a British article on the deployment of the USMC Abram's that discusses the Canadian and Danish Leo's.
http://www.thinkdefence.co.uk/2010/11/usmc-panzers-to-afghanistan/