I have two questions:

1) How long is awal waqt of Salaah?

2) I wish to pray zuhr and Asr separately, as well as, maghrib and isha separately. This so that I can spend more time in Taqibat of each salaah as praying both together with their taqibat takes much of my time and it can create hurdle to my other schedule. Although at the same time i wish to pray at awal waqt. I was wondering if we can hence pray asr and isha an hour and half later and would still be considered awal waqt of Asr and isha prayer?

1- From the start time, the time you need to accomplish your prayer.
2- No problem.
In fact, it is better