Engine-related matters? Perhaps. But Russian birds like MiG-29 and Su-30? Very unlikely.
Pakistan operates a healthy number of Mi-17's by the way.
The Russians would never sell offensive equipment to Pakistan. India is Russia's most important military customer, and they won't endanger that relationship. Pakistan strategically and historically aligning itself with NATO may also be another factor.
And why would the Indians be worried about China having Su-35 technology when China had been operating Su-30's for over a decade? Not to mention licensed production the Su-27SK (J-11) since the 90's?
All of your points are actually easy to address.
First off, I never claimed that Pakistan would ever get Russian planes, even if they could, the Pakistanis don't operate Russian fighter jets, so they won't know how to use them effectively. Pakistan has also been receiving Russian engines from China for a while, with Russia being fully aware and not interfering.
Second, yes, I do know that Pakistan operates the Mi-17, it also operates the Mi-35s, but those aren't fighter jets.
Your third point, I do agree to a major degree, but I have to mention that this isn't the cold war era. Russia is willing to do make allies of former foes, and yes, Pakistan was a foe to the former-USSR.
Finally, India isn't worried about the sale of the Su-35 itself, India is worried about the engines on it, the 117S engines. In case you didn't know, the 117S is being used to power the PAK-FA/FGFA, Russia and India's 5th generation fighter. China has for a long time now, been unable to get past certain road blocks quickly enough to build their own engine for the J-20 and J-31, both of which are China's own 5th gen fighters. India is worried that if China gets the 117S engine, China will be able to look at the engine and get past those road blocks very easily, China being India's main competitor for regional dominance, followed by Pakistan who's China's ally and most likely first customer of the J-31, India is worried that this will both force India to boost defense spending, which India doesn't want to do, and will harm it's regional relationship for neighboring nations, while boosting China's. Not to mention that India doesn't want to be surrounded by all sides with nations that are friendly to China and Pakistan, all of whom have next generation fighter air-crafts.
