I love it this way, when I beg for critical talk there are critical talkers in the party:) Let me turn your conclusion into a new question that provoke more thinking:
So yes, the cost of bitcoin mining is (to some extent) not very important to the price of bitcoin.
The mining cost relationship to Bitcoin has been discussed multiple times. For example, April 2014 mining cost is at $528 coins, close to the price and may influnced it - could be behind the 15th April rally, to return to the right price. It seems the most popular theory is that mining cost grows after bitcoin price, and holds a bottom before the next wave of Bitcoin price rally. So bitcoin demand drives mining cost on the way up, and mining cost decide Bitcoin price on the way down. I lean towards this popular idea.
Also, it seems you argue that bitcoin mining in China is more efficient. If this has any effect on bitcoin's price, I'd say bullish as Chinese miners won't need to sell much bitcoins to cover the cost, and these miners are the people who won't give a shit to CCP's propaganda.
'efficient' is perhaps better replaced with 'externalized'. Now: Suppose the Chinese miners, inefficient as they may be, got free energy (Guanxi again) and produce more coins, since they compete with the world for production, the more they produce, the less the rest of the world can do. Now suppose they hold the coins, only selling a part of it to cover the cost, let's not consider the pressure they cause by selling the coins, but look at the competitor in Antarctica. The Antarctica guy find it is harder to generate a coin, and each coin they generate costs higher. So the Chinese does not have to sell all his coins to influnce price, because the downward price's bottom is decided by the Antarctica guy who has to sell most of his coins to cover the cost. Therefore, instead of worrying Chinese fire-sales driving down the bitcoin price, the opposite happens: that Chinese cheap coins drivers up the difficulty and thus the cost of average coins worldwide.
Now let's go on this direction further, consider competition between the Chinese ourselves: eventually it will drive up the cost of coinage that makes Antarctica miner stop producing coins. Suppose eventually only Chinese and those who externalize the cost (let someone else pay) produce coins. So the cost of coins, the 'list price' to the world will be higher than the cost of coins actually produced at all. The question is: will the bottom price be held by the list price, the supposed cost of minting a coin, or it will be held by the actual cost, the money Chinese has to spent to mint each coin? A more interesting question is, whether or not this follow the cold rule of math or mentality of miner business owners?
This is what I mean by saying 'the mining cost is not directly based on electricity cost in China':
When that happens, China still have 'influnce' on the price if you believe in the pricing model that Bitcoin market price homes mining cost. I put a quotation mark on 'influnce' because it is superfacial: even if China produces most new coins, the mining cost is not directly based on electricity cost in China - it's a long topic on its own.