Directly addressing OP's questions:
Fairly credible, but missing a lot, and mostly lists events from Indian perspective.
Yes, no doubt we lost. Strategically, tactically (by the end), and diplomatically.
It's important to acknowledge and then learn from failures and defeats, those who don't are doomed to repeat them.
Is gen pervaiz musharraf is sole responsible for this ?
Yes, Musharraf is to blame both for starting the conflict, and for losing it despite what he claims today.
Well almost...
You have to assign some of the blame to others of the
Gang of Four who aided him.
And a much smaller proportion of the blame is assigned to the civilian government and ex-PM, any competent civilian government in an actual democracy would never allow rogue generals to go unchecked as Pakistani civilians are always forced to do.
Did Pakistan army refuse to collect the corpse of martyred soldier bodies?
Yes. This is a hard fact for us to swallow, but it's especially true of the early stages in the conflict.
Remember, our official line was that these are 'non-state actors'. Freedom fighters/Militants without the support of the Pakistani state or army. When Indians had possession of martyred NLI and other jawans, including NLI officers, our official stance forbade us from acknowledging them as our own. That's not to say we didn't collect bodies of martyrs at all, we did. And it is damningly indicative of Musharraf's guilt and incompetence.
I read all this on wikipedia and i m blown right now!
I was as blown away as you were when I learned the truth reading about Kargil, we were fed propaganda by Musharraf post-coup. He had to save his skin, had he not have staged a coup, he would have been court martialed for Kargil. And of course India and Pakistan, like other states, cover up failures through propaganda.
Indians are busy doing with Feb-27, we've been doing it about Kargil. Although now facts of Kargil are far better known and confirmed from our own sources too. The truth always wins out.