For information as to the extent of Soviet military aid to the Republic, and the considerable risk and losses the Soviets took in furnishing this aid - read "Soviet Military Aid to the Spanish Republic in the Civil War 1936-1938" by DC Watt, published in the Slavonic and East European Review. It is not fraudulent scholarship like Gerald Howson's Arms for Spain, which just makes up stuff out of whole cloth. It comes from primary sources. What is interesting is the extent to which the Italians engaged in piracy to destroy Soviet aid shipments, and considering this was during the height of Italian-British reproachment, the fact that nobody in the Non-Intervention Committee gave a damn about what the Italians were doing, in fact they were openly aiding the Axis. Nobody mentions the shameless duplicity of the Non-Intervention Committee at all, instead they heap abuse on Spain's one real ally. The Non-Intervention, coupled with anarchist and Trotskyist putsch attempts, ensured the fascist takeover of Spain. One of the sources you cite, Beevor, says as much. But not you.
Furthermore, people in the International Brigades, not anarchists playing at revolution with Francoist agents in Barcelona, point to the fact that it was Soviet trainers who taught them how to fly a plane, Soviets who taught them how to shoot a gun, and Soviets who taught basic military tactics. On the hand, the anarchist revolutionists completely sabotaged Republican war efforts from the beginning by forcing the disbanding of the 8 pre civil war army divisions which had remained loyal to the Republic. The Republic then had to rely on party militias and lacked professional officers. This, combined with the fact that the Republic had to waste precious resources putting down illegal anarchist occupations of telephone exchanges (which were defended with machine guns, of course they couldn't be used at the front, could they?) and other uprisings.
As for the so-called "plundering of gold", a sizeable portion of Spain's gold (at least 1/5) also went to France. Did France steal it? If the Soviets were interested in swindling the Republic, why did they repeatedly sell Spain weapons on credit? After all, the gold reserves supposedly ran out in 1938, but yet Spain kept getting weapons to continue the fight. Furthermore, before any gold had arrived in the Soviet Union, the Soviets had already sent - > 187 aircraft, 147 tanks and armored vehicles, 114 artillery guns, 3,703 machine-guns, 60,183 rifles, 95,528,860 rounds of ammunition, and 150 tons of gunpowder. The material that was sent, far from being "shoddy", was superior to the German and Italian equipment, particularly the tanks and planes. The Soviets sent around 900 tanks, these tanks were equipped for a 45 mm gun, and were more powerful than the small tanks the italians and germans provided that had two machine guns (150 Panzerkampfwagen Is, 7.92 mm guns ). Howson talks about the poor quality of rifles but the Nationalists had Italian guns from 1893. In all the Soviets provided something around 415,000 rifles to the Republic it supposedly "betrayed". In addition, the Spanish never paid for at least $50 million worth of material they received. So, this idea that the Soviets somehow stole the gold or ripped off the Spanish is complete horsepuckey invented by Gerald Howson.
And what people like Howson and anti-communists refuse to acknowledge is, aside from the use of the gold reserves, thanks to the damned "Non-Intervention" Committee, there was no by which the Republic could get arms to fight the war. The gold in the Soviet Union was used to set up an account with the Soviet State bank to make payments on arms sales to numerous foreign countries. The same thing happened in France, where the Soviets had a front account through Eurobank. No Spanish historian who has investigated this matter has concluded that Spain was defrauded.
Finally, the idea that the status quo is afraid of anarchism is a joke. Anarchists have never posed a real threat to anything, which is why you were forced to bring up Spain as the only real example of anarchists having any influence. What revolutions are anarchists leading today? Absolutely none. I can point to many being led by Marxists. And I can point to many Marxists being arrested and/or executed (or outright murdered) by the authorities of many countries. Not so with anarchists. Most anarchists are lifestylers who do little to no political organizing, preferring to live their morally pure life outside of society.