It is already minimized.
"Access your data on all web sites": to be able to filter out any anti-blocking script on websites
"Access browser tabs": to be able to shut unwanted popup
"Access browser activity during navigation": to handle active tabs which keep checking adblocker in background
You are welcome to ask in issue tracker if you still wonder the need of these permission https://github.com/LiCybora/NanoDefenderFirefox/issues . I will also document out them soon.