You can submit EAD at the same time when you submit 130 and 485. Usually 1-2 months. If you don't receive EAD card 3 months after the receipt of your application, you can walk into any field office to get the card right there.
2.多長時間才能拿到綠卡?是條件綠卡還是正式綠卡?
It is different depending on where you apply for it. I submit my application at end of May. I have received my actual card in Sep. It is conditional green card.
3.一般來講,我有必要再延期H1嗎?
No. You can use your EAD card for work.