From Quetta you will have the following options,
Quetta to Sukkur to Multan to Lahore.
Quetta to Kashmore to DG Khan to Multan to Lahore
Quetta to Zhob to DI Khan to Islamabad.
I would suggest to stick to route 1 which is the busiest. The 3rd option crosses through Waziristan and is currently closed for foreigners.
I have heard that nowadays police escorts the motorcycle travellers till Punjab making the Pakistani carnets expensive. Mid February might be cold in Balochistan but sparing 7-10 days for Pakistan might be unfair. Pakistan is the world's best kept secret and you might need more time to explore it sufficently although at my age i feel even a lifetime aint enough.
He Omar you are the same person who has Contact whit Aswhani?
i got your phone number? and sent you my e mail adres?
we stick to your advice, and who know mayby we spent more days in Pakistan......
we like to surprice ourself, and find out.
we are open for all kinds off improvment for quality time in Pakistan.