However, as for these other translations such as "disaster" and "calamity," they don't serve the loving nature of god much better. They imply the loving and just god of Abraham specifically brought disaster and calamity into the world, which is hardly an admirable thing to do.
Disaster and calamity would seem to be inevitable effects of the nature of the universe. If what you are really asking is "Why did God create this universe, rather than some other universe," that may be a perfectly valid philosophical question, but I confess I do not find it a compelling one: this is the universe we have. This is what God created. Since God is omnipotent, I think we can only presume that this was the model of universe that He decided would work best. And either we are willing to trust that He is doing the best He can, and we move on to the more practical issues of how we live in the universe we inhabit, or we do not trust, and we never get past primordial issues of metaphysical cosmology.
Personally, in any case it seems to me that as disaster and calamity has to do with forces of nature, which were here before humanity, and will be here after humanity is gone, it hardly seems likely that God intended them personally, and we have no reason to take them so.
But there's no reason to require the two be parallel.
Deconstruction of Biblical poetry into parallels and chiasms in order to better understand the often abstruse usages of words by Biblical authors is a standard technique of academic Biblical criticism. The presumption is that parallels were indeed an important literary device, and authors wrote relatively strictly to those forms. I have done nothing that is at all unorthodox or uncommon in Biblical criticism with this speculation, so it seems to me that you simply do not like the techniques of the field. Which is fine, of course, but it seems like it limits the possibilities in reading the text.
Your apologetic here suggests god created order and chaos just so he could express himself poetically.
God did not write Isaiah. Isaiah (or at least, the School of Isaiah) wrote Isaiah. Even if the author is faithfully setting down the prophet's account of his revelatory experience, it is still dependent upon the prophet's comprehension of what he has experienced, the comprehension of the author of what the prophet has related, and even then is subject to the need of the author to cast the experience into the poetry of song. In other words, your construction of what you term my "apologetic" is by definition, backward.
Evil, on the other hand, is not a necessity.
Since you do not accept a doctrine of free will, I can't help you. I don't pretend to understand how the universe would work in a paradigm without free will.
Sorry, but straining to turn ra', with its primary meaning of evil into chaos, not even a listed meaning by Strong's, is too much of an apologetic stretch.
Strong's is hardly the last word in translation. There have been any number of occurrences of words in Biblical literature that were thought to mean only a certain number of things during the era of their writing, which later scholarship has demonstrated could have meant yet another thing, based on later usages that were then found to have earlier precedents as the archaeological record has expanded.
In all, I think it's fair to assume that the translators of the Bible used the words they did because that's the meaning they wished to convey.
Up until extremely recently, translations of the Bible were absolutely notorious not only for mistranslation, but for utter deafness to the use of idiom, slang, hyperbole, double-entendre, punning, and other such devices. Even today, very few Bibles come anywhere close to accurately translating even the literal meaning of the text as a whole, let alone what the poetic implications of the denser prophetic texts might be. And in any case, between the original intent of the authors of the text, and the best practical understandings of today's readers to aid in relating to God and living a good Jewish life, I see little relevance in the motivations and priorities of non-Jewish translators. If one is bound and determined to adopt the texts of another tradition into one's own, without context or tradition of interpretation, then IMO, any undesired consequences are one's own affair.