Re: Charging on the headphone plug: not a good idea
Sure, I guess you could put together a super-complicated charger like you're talking about, but I've got an easier and cheaper solution: just charge from a Micro-USB socket instead.
Yeah, it really is a better way, especially since the headphone/mic jack isn't "intelligent" at all in the way you're talking about; it's just mono in, stereo out, and ground, without any negotiation capability whatsoever. (Why would you expect any different out of a socket that's intended to accept headphones? The basic design hasn't changed since it was invented in the first place!)
I wouldn't be surprised if there's a bit of protection circuitry behind the jack, but I wouldn't expect there to be much, because nobody uses that kind of connector any more for anything that can't safely be plugged into a headphone jack -- you sometimes see it used for power on old stuff from the 70s and early 80s, but never on anything newer unless maybe cheap Chinese crap no one in his right mind would buy. (And anyone who takes a male TS plug from a crusty old 9VAC wall wart, and sticks it in a headphone jack, deserves to let the smoke out anyway.) The connector is just not meant for power -- leaving aside all else, you can short a TRS plug by looking at it crosswise -- and no one sensible is going to listen when you try to convince them otherwise.
(And good luck getting anyone to stuff a 2mm two-conductor barrel jack, which is what I think you mean, into phones which nowadays are around 5-7mm thick and getting thinner. If you're talking about a connector even larger than that, well, good luck, Grandpa...)
As for your problems with the Micro-USB socket, I don't know what to tell you other than that nobody I know has problems like that, despite the increasing ubiquity of the format. If the cable's dragging out the guts of the socket or something, maybe you should try slightly less cheap cables. Less extraction force, maybe?
Finally, a useful note: The USB standard specifies that plug-ends with tactile features, such as an inset or bumped-out USB logo or similar, shall have the tactile feature on only one side of the plug surround, specifically on the same side that's 'up' orientation for the connector itself -- that is, if the tactile feature's facing up, so is the connector. I'm not as familiar with the part of the standard describing how the socket should be implemented, but based on experience I suspect it's similar -- that is, when the device is facing upward, so is the socket. Combine this knowledge with your body's inbuilt proprioception capability (that is, knowing where its parts are in relation to its other parts), and you've got the problem solved -- get the device and the cable into known orientation, each in one hand with index finger tip on the connector; bring fingertips together; move fingertips out of the way and complete the last half-inch or so of the connection.
The trick works great in the dark, Parkinson's sufferers and others with fine motor control problems possibly excepted; it may not help you while driving, but what the hell are you doing screwing around with cables when you should be driving in the first place? Charging your phone is less important than not killing somebody in a traffic accident!