We should get out..but before doing so..do 2 things..
1. Ask them exactly what they want. Whether that be we build them something or whatever..and we do it.
2. Leave..but remind them that if they engage in the same sort of nonsense they engaged in before..we will be back. And the next time..we won't be sending in any troops. It will all be indiscriminate bombing.
Once we are out..we maintain an intelligence presence ready to wipe out any "noise makers" quickly. We also make ourselves available to them if they ever want to construct a sensible and coherent government.
The first thing you suggested would be very difficult to do because Afghanistan is a very fractured country, the people there are more loyal to their tribe than their own country. There are many different cultures, tribes and languages in Afghanistan, you could go to the north of the country and people will speak Tazik, Hazara and even Turkish, in the south they are mainly Pashtun and thats where the Talibans main base is. In the west there are alot of Afghans with Persian roots who speak Farsi and have ties in Iran, each of these different tribes and cultures will have a very different answer to your question, the Hazaras, Uzbeks and Taziks in the North would probably like us to stay and help rebuild their country while the Pashtuns want us gone yesterday.