To the first, maybe. To the second, also maybe, but I saw the Shire section as being more representative of the experience of soldiers returning home. Like, Frodo and co. come home, find everything's changed. Of course, the changes are due to Saruman, but that's the subtext I took from it.
There's no "maybe" to it. He laid out the whole-ass case to Christopher in Letter 73, a rare character break for a man that decried allegory and symbolism in practically each and every other case. At least, such as it's understood in the oft-decontextualized quote from Letter 181, after which Tolkien is quick to remit his belief fairy tale and epic still are influenced by and reflect truth of the human condition and society, albeit in their own way divorced from simple commentary or allegory.
Flowing from that, the true evil in Tolkien's work was technology, industrialization, and the will to power. Sauron, Morgoth, and the "forces" of evil were a vehicle for it, and the world is teleological in the sense corruption is unavoidable and revivalism is not possible; the best one can hope for, is temporary palliation. It's telling Sauron's act of "original sin" (at least in the context of LotR rather than later works which filled gaps in Tolkien's legendarium) is an act of deceit and
mass production; expanded in later work to identify Sauron as originally a servant of the Aule the
Smith (the other noteworthy servant of Aule being
Saruman).
That'd be the same Aule who taught Feanor, who would go on to create the Silmarils and Palantiri, and who created the dwarves. The through-line I'd like to point out being, Tolkien adapts a highly Boethian argument for creation and teleology; the act of creation itself being inherently corruptive, insomuch as a creation reflects the will of its creator and can only be less "perfect" than who created it -- or who appropriated it for their own use.
So, the question is: regardless of what real-world cultural archetypes Tolkien drew upon when writing the dwarves (Norse mythology as befitting a lifelong study of Germanic mythology, not Judaism), are they presented as necessarily or inherently evil, or a flawed creation?
And if you want to argue that the goblins are subconcious anti-semitism, that's an easier hill to climb, but I can't help but disagree. As I've stated, there's too many similarities between the goblins of HP and the goblins of folklore for me to consider that the more likely option.
How exactly does the wizarding world at large treat goblins, again?
Even "progressive" wizards who advocate for "magical creatures" welfare tend to not think twice about goblins. In that light are goblins really a conspiratorial cabal of bad actors straight from the pages of
Protocols of the Elders of Zion, or are they defending their communities by using the societal role forced onto them, and the leverage available to them?
I mean, you can talk about Nazism all day. Nazis invented neither ghettos nor pales of settlement, nor did they invent blood libel, ban Jews from labor organization, or exempt Jews from lending and tax collection because those were perceived to be "sinful" trades. That was medieval Christianity.