(Original post by *Funky-buddha*)
I don't mean to offend you but the word 'pathan' was originally considered derogatory hence you will find numerous objections to it by pashtuns. Many of my Pakistanis have told me 'Pathan' is used by them in order to indicate someone of pashtun lineage but has mixed/adopted a Pakistani culture. Like countless others who have mixed with Pakistani people and adopted more so of their culture thus become removed from the whole culture of 'pashtuns' adopting Hindko as their mother tongue, I personally think maybe your case resonates as being at a very late stage of that transition.
For pashtuns, pashto ( and yes I admit along with 'some' Dari influences since the history of Iran and Afghanistan is so interlinked) has always and will always be a mother tongue. Hindko has never been a pashtun mother tongue.
My father goes crazy trying to make sure we learn to speak pashto to a good standard and not lose the language. He's even implemented a pashto only rule, at home. I can imagine his reaction if I was to tell him that I wished to speak hindko as a replacement to pashto, it wouldn't be pretty, it'd be a quick Google search to the most pashtunified place he can find and an ASAP ticket to there for me.
Pashtuns are very passionate about pashtu and I don't believe you can as a pashtun replace that mother tongue.
I mean I've heard people speaking hindko and it bears little resemblence to pashtu with dari speaking pashtuns who've had farsi in their family for years upon end, when they speak it does often turn my head as I can understand a sentence or two and the whole tone is generally very similar sounding to pashtu, in the way they express the words and such.
Don't get me wrong, my mixed race cousins speak as much pashtu as I speak Japenese, but they know that for their pashtun side, Norwegian is not a substitute for their mother tonuge (in regards to their pashtun sides)
I don't know much about the whole hindko thing but researching it further, briefly now I came across this 'Hindkowans who are sometimes referred to as Punjabi Pathans.' which I dunno, maybe you feel due to the loss of language and such forth you fall into that umbrella.
What I am saying is that for me being a pashtun and a pathan are two different things.
( Oh and in answer to your question, I would include someone with a great great grandfather who was pashtun, as being pashtun/ part pashtun if they wanted to be. Your question should be directed to those pashtuns who are very nationalistic or embody every part of pashtun culture whom often like to set the standard for consideration. I mean it was remarked by one charming freshie that my western dress and father's being born here that I wasn't a very good pashtun and he couldn't believe I was a full one blah blah....with them you may encounter problems, namely arrogance ¬_¬ )