Follow-up/corollary: how does this compare with the life of the average person in the rest of China in the first half of the 20th century?
There's a two historiographical problems faced with answering this question.
We have a vast and complex corpus of literature in Tibetan. A quick saunter through my University library will blow your mind. But most of that literature is religious in nature, and what little there is that is historical is mostly geared towards the literate class of monks. This requires a brief understanding of Tibetan society and history, which was only semi-sedentary until very recently (and still features large-ish communities that are nomadic). History, capital-H, preferences the written word, and books are heavy and not conducive to nomadic societies. So the primary sources we have regarding Tibetan history and life preference the monks who lived in stationary monasteries, who controlled (for the most part) the supply-and-demand of paper production, and were literate.
So if any one was to be doing the oppressing, it would have been the monastic establishment. And they would have been the ones with most of the ability to record those deeds, and with the most incentive not to do so.
The most uncomfortable part with parsing apart the history of Tibet from 1912-1950, during the period of de facto independence, is the political ramifications. Ignoring the Simla Convention of 1914, which the Chinese representatives rejected anyway, and the British and Tibetan dignitaries made sure to include a note specifically pointing out that no Chinese had signed the agreement (which would come back to bite India in the ass in 1962), most Tibetan and Chinese historiography in this period is mostly focused around what constitutes political legitimacy and trying to analyze sources and perspectives regarding the same event.
Just take the naming of the event that closes out this period: to Tibetans, it's the "Invasion" of Tibet, while the Chinese government refers to it as the "Peaceful Liberation." Wikipedia has chosen the neutral (but decidedly non-peaceful) "Battle of Chamdo" to refer to the event.
Other events, like the 14th Dalai Lama's enthronement are mired in controversy. At that event specifically: regarding whether the (Republican) Chinese general Wu Zhongxin had a role equivalent to the Manchu Ambans that formerly held representative imperial authority over all Tibetans, or whether he was a foreign ambassador to an independent state. The British representative to the event makes it pretty clear that Wu was not there to preside over the event, but was indistinguishable among the other representatives just as he was. Sir Charles Bell's account on Tibet is invaluable as a source of information regarding this period, but it faces the same problem as above: Bell and pretty much any Western visitor to Tibet was going to be in a privileged position and write from that perspective. Even Seven Years in Tibet which has come under some not-insignificant controversy, comes to a climax with Heinrich Harrer as a tutor to the HHDL XIV.
The claim that Pre-Liberation Tibet was a place of misery and servitude is mostly put forward by Communist propaganda in an effort to justify their political sovreignty over the region. Whether they're using this line to justify aggressive action to their own soldiers in the PLA, to their own people as to why they're engaging in what seems like imperialist activity that they actively denounce, or to try and win over the Tibetan people or Western media, is not entirely clear to me. If it's the latter, which seems the most likely implication, then the consistent stream of refugees from 1959 onward through the Dalai Lama's Nobel Prize in 1989 would suggest that the propaganda machine has largely failed. I tend to think that this claim is mostly put forward to present the PRC to the Chinese population at large as a force for good in the world.
I think there is evidence to support either argument, both with good reasons.
Tibet was never quite a state in the way we imagine independent states having control over an area of defined borders. It was always more of a spider-web arrangement of loyalties with a frenemy home base of the Tsang region (south-central Tibet from Lhasa to Shigatse) and then radiating outwards to various degrees of loyalty and control based around current events. The height of Western travel to Tibet (during the de facto independence period) was concurrent with the 13th Dalai Lama actively seeking international recognition for Tibet, including inviting Western scholars and academics. The 13th Dalai Lama was personally friends with Sir Charles Bell (further compounding that problem about primary sources) and sent a man he hoped would become the first Ambassador to Britain along with four young boys to attend a British school and bring back modern knowledge. One of those boys, according to Van Schaik's Tibet: A History, would go on to develop Lhasa's first street lamp systems.
These Westerners (of whom Bell and Harrer are probably the most famous) see Lhasa at the height of its political domination, precisely because it's the era that Lhasa was actively trying to shift functionally and philosophically from a mchod-yon system to a Westphalian state one.
In my opinion, this by definition would involve a non-zero level of violence and domination. The 13th Dalai Lama struggled to build an army to use in the case of war. The period of 1912-1950 should be a pretty obvious one as chock full of the worst wars of the 20th Century. Tibet, often associated with the term "Shangri-La" (which I've deconstructed before) at this time was decently connected to the world. There was a telegraph in Lhasa, and newspapers that would reach the city only a few weeks after the events they described (miles ahead of Tibet's "closed country" status of the 19th Century).
Yet, the efforts at building an independent Tibetan army were shut down pretty quickly, and no moderately effective fighting force seemed to ever have developed.
For evidence of the kind of violence needed to suppress local resistance, we don't need to look any farther than Drepung Monastery within the confines of Lhasa:
For many, especially the monks, Bell was an unwelcome presence, and signs were put up around the city urging his assassination... Bell also heard the arguments of the abbots that the Dalai Lama’s army was against the Buddhist principles that were dear to Tibetans. Knowing full well where the opposition to his policies was strongest, the Dalai Lama made a preemptive strike, arresting three of the Drepung abbots. They were charged with unspecified crimes, punished by whipping and sent into exile. The monks of Drepung were electrified. Ignoring the pleas of their abbots, they poured out of the monastery in their thousands, heading straight for the Norbulingka, the Dalai Lama’s residence... The armed guards at the walls of the residence were unwilling to shoot, so the monks took their guns and broke them. Then the senior monks prostrated in the direction of the Dalai Lama’s residence before shouting their protests. Some of the junior monks were less respectful, pulling up flowers, smashing statues, and urinating and defecating in the Norbulingka’s ornamental gardens. Inside the residence, the Dalai Lama sat tight and waited for the storm to pass. By nightfall the monks were drifting back to their monastery. The next day, the Dalai Lama wasted no time in mobilising his new army. The seven hundred soldiers in Lhasa were given live ammunition while those in outlying districts were summoned back to the capital. The troops began to lay siege to Drepung, which appealed to the other two main monasteries for support. Sera, always the most loyal to the Dalai Lamas, refused outright, while Ganden wavered for a few days before siding with the Dalai Lama too. As Lhasa families began to hide their valuables, more and more soldiers arrived, until there were three thousand of them surrounding the monastery. At Drepung the rebel monks knew the game was up. They held out for a few days, putting up signs bearing messages of protest above the monastery walls. The chief ringleader of the revolt slipped away, but was discovered hiding out in a cave in the nearby hills and brought back to Lhasa for punishment. So ended the revolution. Within a few days all was calm again and the new army paraded through Lhasa in full British-style regalia, before presenting arms in front of the Potala where the military band played ‘God Save the King’. The Dalai Lama treated the monks leniently but took control of the appointment of Drepung’s new abbots and banned Khampas from taking high positions at the monastery. [Van Schaik 197-8]
We still face the problem that both sides of this conflict were privileged elites. Plus, being political rivals with an event ending in violence (especially a kind as mildly described as this) is hardly what's intended when we question the "misery and servitude" of Pre-Communist Tibet.
Cont'd
would love to see more discussion like this.