Now before I begin, let me say that I am in no way advocating the release of harmful toxins such as refrigerents into our mother earth .

That being said, please elucidate for me (because I'm the sort of person who likes to know everything about his car) if there is like a bleed off valve along the a/c line that when remained open will release the 134a from the system, for emergency purposes of course. Does the compressor need to be engaged when it'* open? If such a valve exists, where can i find it? ('96 Bonneville)

If your compressor is running when you vent, you'll run the risk of burning up the compressor for lack of oil. The oil is intermixed with the R134.

The high and low side fitttings are on the belt side of your engine going too and from the front and back of the engine bay. One is larger than the other under plastic caps. Near the accumulator (aluminum can covered in black insulation).

A slight warning. The oil used in a 134A system will harm if left on skin for any amount of time. I hear it tingles immediately when it comes in contact.

so while the car is off, press on the high side and low side service ports? I'm guessing wearing gloves is probably a good idea. Or perhaps fitting a special tube over it like from a retrofit or recharge kit.

Can this be equated to something like the little valve on a bike tire inner tube where the center needs to be depressed by a bike pump?

Yep.

Called a schrader valve!

Doing that is going to spew oil all over the car. That can't be good.

Just theoretically of course, if one were to do that, would one have a REASON to want to do that?