If you had to omit one part

[The Squatter of Amon Rûdh]

As an addendum to the above, I have a couple of quotations from Tolkien's letters to share with you. Both of them refer to The Lord of the Rings, although I think that they are equally pertinent to the legendarium as a whole:

It is written in my life blood, such as that is, thick or thin; and I can no other. I fear it must stand or fall as it substantially is.

...every part has been written many times. Hardly a word in its 600,000 or more has been unconsidered. And the placing, size, style, and contribution to the whole of all the features, incidents, and chapters has been laboriously pondered.

I would say that this is reason enough to leave well alone, even in speculation. Tolkien put a lot of himself into his work over decades of writing, and it seems to me an insult to his dedication and ability to suggest "improvements", especially where they seek to cut certain parts of his carefully considered narrative for the sake of personal taste.