Pop- No problem, we are all seeking best practices here.
I don't have a 'scope, and I sure can't say what people's chargers put out precisely, but the Pi people built-in the visible voltage warning for a reason, so I'd suspect the Pi is vulnerable to voltage fluctuations. It certainly isn't hiding behind a sophisticated PSU like a typical mobo.
I've read of many people using unrecommended power- that guy with the shock wasn't getting 5V from the Pi, he was getting voltage passed thru from the TV monitor.
As far as the card issue, there is another guy right here who is using the TV's USB to power the Pi and is getting very frequent corruption. Here's what popcornmix said about that:
"More advanced sdcards implement background wear levelling and aggressive write caching to improve performance.
These produce a longer window where sdcard activity may be occurring (even when Pi appears idle).
If you cut power while an sdcard is moving sectors around (for wear levelling purposes) then corruption is likely."
http://forum.kodi.tv/showthread.php?tid=222715&page=3
As far as shutdown time, I timed it from clicking Shut Down to a steady red LED on the Pi. It's a Pi 2B.
edit: here is the thread about the shock
https://www.raspberrypi.org/forums/viewt...8&t=101738