I'm not surprised at the reaction the renaming of the NWFP has provoked. The whole fiasco of province naming and its history is a measure of utter lack of competence of Pakistan to solve her issues small or big.
For decades Hazaras sit back and relax with NWFP - the British given name that stopped making any sense the time Pakistan was created. And now, they rise up to kill and get killed on the mere naming of the province as Khyber-Pakhtunkhwa! No educated, civilised person would be out on the streets like those crazies. Protest against the renaming as you wish, but for Heaven's sake have some sanity. The nature of protests whenever confronted with a controversial issue tells what a violent society we have become.
On the naming, renaming and division of provinces: -
Altering the existence names and demarcations on purely ethnic/linguistic lines would create more problems than solve. New provinces should be created and current ones named/divided on the principle of efficient administration and proportional distribution of resources. If people had their fair share of economy and social stability, no such ethnic/linguistic issue would arise in the first place, at least not with this intensity.
The problem with ethnic/linguistic demarcation is that no existing Pakistani province has homogeneous ethnic and/or linguistic population. An attempt to do so would require the redrawing of the borders of all of the 4 [5?] provinces. The division wouldn't be for administrative purposes but to satisfy the egos of illiterate and half-educated masses, and hence serve no purpose.
The Punjab itself, the southern region, is dominated by Seraiki speaking people who demand separate province. Despite the dishonesty of Punjabi intellectuals elite, who claim Seraiki to be no more than a dialect of Punjabi, Seraikis themselves do not identity themselves with either Punjab or Punjabi language. You know about the movements for Seraiki and/or Bahawalpur province(s).
Balochistan sounds like it is overwhelmingly Baloch and Balochi speaking while in fact it is no more than 55% ethnically and linguistically Balochi. The northern areas are inhabited by Pakhtuns who speak Pashto including the provincial capital Quetta itself.
Now the so-called Khyber-Pakhtunkhwa. It has a large population of Hindko speaking Hazaras who do not identity with Pashto or Pakhtuns.
Take a look at Sindh. The Sindhis are but a small minority in the provincial capital Karachi, thanks to post-partition migration. The cities of Sindh are in substantial part inhabited by non-Sindhi speaking people mostly what are called "Muhajirs".
I am for dividing Punjab into at least two if not three. Rawalpindi and other areas can be grouped together. Central Punjab can include Lahore, Faisalabad, Sahiwal etc. The Southern Seraiki Belt should be turned into a province. Don't call it Seraikistan if you don't want. Call it Multan Province of Bahawalpur Province or something else. Same is true for Balochistan. It should also be divided for administrative purposes. It is a backward and too big a province to be run from Quetta.