Does a poem...?

[Leanne]

Does a poem…?
…need to be PC? (as an absolute / within individual definitions / no not really…”let’s not and say we did!”…besides which we are being radical poets and nobody can second say the art)

No. A poem needs to be what the poet wants to say. Deliberately trying to be non-PC is a bit passe, but there is no such thing as an unpoetic subject. Poetry gives us a vehicle for difficult, dangerous and dirty ideas that wouldn't work in any other shape. Poetry sometimes comes in beige but it's more interesting in shades that sometimes defy the rules of good taste.

…need to have an understandable, or at least some level of discernable meaning? (that is “accessible” to all / a select few)….or alternatively is it only about the relative sounds made by the units of words that is of significance and meaning is only secondary?
(I’ve no doubt there are other points that could be discussed, but these were the most recent two on my horizon).

As Ray said, everything has a meaning on at least some level. Some readers are resistant to finding it, especially if it's not immediately apparent. We have been exposed, over the past twenty years or so, to the idea that if it's difficult, there's always a shortcut somewhere. Spark notes destroy poetry.

This runs into problems when everything about a poem is forgettable, of course. If it doesn't have interesting language, unique imagery or ideas that spark the imagination it will make no impact on the reader at all. In the immortal words of Hector from The History Boys, (which I always quote because it's true): "...I never understand it. But learn it now, know it now and you will understand it... whenever."