Safari Extensions – Allow Safari Extensions to Access Files

After starting Safari, you can go to History -> Reopen All Windows from Last Session to have Safari reopen the windows and tabs that were open when you last used it.

There's some additional info in this question: Is it possible to restart an application using AppleScript?, including a script (Chealion's answer) that can be modified to start Safari and call that menu automatically.

It's primarily a matter of parsing the output of defaults read ~/Library/Safari/Extensions/extensions and formatting it in a user-friendly way. The result actually answers both of your questions:

defaults read ~/Library/Safari/Extensions/extensions | awk '
/Bundle Directory/ {
    split($0, t, /\"/);
    sub(".safariextension", "", t[4]);
    sub("-1", "", t[4]);
    bundle=t[4]
    e="disabled"
}
/Enabled/ {
    e="enabled";
}
/Hidden Bars/ {
    print bundle, "...", e
}' | sort --ignore-case

Creating a shell script out of it is left as an exercise to the reader.

Please note that this will most probably stop to work if Apple decides to change the format of ~/Library/Safari/Extensions/extensions