One could consider the Taliban as "ultra-orthodox" Muslims. I don't dispute that there is a spectrum of orthodoxy among Muslims, just as there is among Jews and Christians. The crucial question is how many orthodox and ultra-orthodox Muslims we have, since that end of the spectrum can be expected to be the most dangerous.
The phenomenon of the Taliban in Afghanistan and Pakistan, (and this is just my personal opinion) is tied to the Islamic concept of zakat (erroneously described as charity for the poor).
Zakat (for the benefit of other Freepers) is an obligatory tax on Muslims, computed as 2 1/2 percent of the wealth of the person (above a certain threshold). The poor are not the only recipients of zakat. Zakat is also payable to clerics, Islamic students (Taliban) and for the financial support of those engaged in Jihad. It is to the benefit of the Taliban to be strong advocates of orthodox Islam, since they are financial beneficiaries of the zakat tax, and their being engaged in preaching fundamentalist Islam and engaging in Jihad is what legitimizes their demands for financial support via zakat.
All very thoughtful points you make. The Taliban-Zakat phenomenon is certainly something that needs to be closely examined