No, absolutely not, to the last sentence (agree with the first two). The buffer doesn't have anything to do with protecting the channeler from the damage of overdrawing. Otherwise, Rand would have faced such damage using Callandor.

All a buffer does is prevent you from drawing any more than your own potential+whatever the angreal contributes. Exactly like a link, where the buffer means you cannot overdraw, or make one of your linked partners overdraw.

This is explicitly disproved by Rand using Callandor to great effect without burning out.

All the buffer does is make sure you don't go beyond your strength+angreal strength. An angreal lacking a buffer does NOT become useless.

OH FOR FUCKS SAKE! You're being incredibly dense about this, and I'm very confused as to why.

Let me break it down:

Random channeler has strength X.

An angreal she has adds a strength of Y.

If the angreal has a buffer, she can channel strength X+Y, and no more. However much she strains, or tries by accident, she cannot draw more.

Lacking the angreal, she can draw X+astronomical amounts of the OP (Z); like Lews Therin in the Prologue of EotW; but she will either burn out or die.

If the angreal had no buffer, the channeler can draw X+Y+Z. The Z part doesn't come from the angreal! The angreal is still only giving the channeler an added Y units of strength. Any extra drawn is the channeler overdrawing, and since the angreal has no buffer to prevent it, the channeler can do so. But the added strength is NOT from the angreal. I find it mystifying that you think it has to be.

You brought up glasses, so here's another analogy:

Channeler is a glass of capacity X units of saidar.

Angreal is a glass of capacity Y units of saidar.

So when channeler uses angreal, total capacity is X+Y, and the buffer is a nice tight hard limit on the tap placed by the angreal which prevents more saidar than X+Y from being drawn.

When the angreal doesn't have a buffer, there is no hard limit on the tap, so now you can keep opening the tap more and more, which causes the channeler glass to break from the strain, burning you out or killing you.

Then how the heck can there be sa'angreal that work, but have no buffer?

Okay... what changed about the buffer-less angreal when it went from 2X to (2+)X? Why can THIS version of angreal suddenly multiply more than the intended spec, but the additive version can't add more than spec (not that I believe it needs to)?

There's something really weird about your argument here. You seem to think multiplication beyond the "safe" value is okay, but not addition. Can you explain why this is so? Both are equally unlikely, actually, but you keep insisting that it is ok for multiplication. I just can't figure out WTF sort of logic that is.