I never know China or Russia has so much influence on Iran as you said. For Khomeini, US was the grand Satan, USSR was the junior Satan, and we Chinese were commie kuffars, neither could be trusted, and apparently his will has been inherited.
IRI has been the most independent regime in the world so far, and its cooperation with Russia and China is all out of national interest. I see no country can push IRI to obey, even the US sanctioning IRI for 40+ years.
Mentioning Qatar, so you must know it was Russia that tore Azerbaijan from Iran like what China suffered in the same era, but it doesn’t matter you cooperate with Russia now. We don’t owe Iran historically, and in fact Sino-Persia relation had been friendly since ancient times, the last prince Pirooz of Sassanid Persia was sheltered in China.
If there are our agents in your leaderships, then our investment would be far more than now, but the reality is we are blocked to some extent. Conspiracy doesn’t lead to success.