Whether H1B Extension is required if Amendment approved for Next 1.5 years

Please understand my below case.

My stamped visa already expired in SEPT-2017. I did NOT moved out of US and still with same employer.

My extension got filed when I was with on project A. I moved to another new location by filing amendment while my extension was PENDING for approval.

From new project location, I converted my H1B extension into premium & got it approved till SEPT-2018 while amendment was PENDING for approval.

Recently, I got amendment approval with renewed i94 validity till OCT-2019.

Queries :-

  1. Can I consider amendment validity as my visa validity?

  2. Whether I need to file H1B Extension again as earlier H1B extension request approved till SEPT-2018

  3. Can relocate to another location by filing new amendment again?