For your second point: If you suspect lines are live, you shouldn’t be messing with them at all. And don’t trust those little AC detector probes that light up and beep when they detect power nearby. Electricians call those widowmakers, because the apprentices will trust it, it fails to detect power, then the apprentice gets shocked because they think they’re working on dead lines when they’re actually live.

If you absolutely must check it without a proper multimeter, use the back of your hand, not your palm. It will cause your muscles to clench when you get shocked. So using the back of your hand will cause you to flinch away from the shock; If you use your palm or fingers, there’s a good chance that your muscles will contract around the wire and you’ll be “stuck” to it until someone else kicks you off.

Lastly, if someone nearby is being shocked, don’t grab them to pull them off. For the same reason as stated above. Your muscles will all lock up as soon as you grab them, and you’ll get stuck too. Kick them off instead. Kick hard. Like a full blown Sparta kick. You need to kick so hard their hands are ripped away from whatever they’re locked onto. Or if they’re not in a place you can kick them away, take off your shirt, twist it up, loop it over their shoulders, and pull. And again, you want to pull so hard you knock them completely over and rip their hands away from the electricity.