Not everyone had more or less the same lifestyle. If nothing else, you had central cities and peripheral towns and villages, and Russia vs other Soviet Republics (I know Ukraine got the shorter stick, to say the least for a very long time if not all the way to the end), etc.
I don't think so. It's probably a propaganda of the new independent Ukraine government since 1991. Many of my relatives are stuck on Ukraine now because they moved there during USSR times because life there was better. They'd be happy to return to Russia, but they're old and they are citizens of Ukraine and if they sell their property in Ukraine, they'd be unable to buy real estate in Russia, so it's almost impossible for them to return. And they regret that dearly because of politics of nazism and poor state of economy.
Not all republics in USSR were equal, but differences weren't as big as they're now. And contrary to what current propaganda says, most prosperous republics were Baltic republics and Georgia. USSR was investing a lot of money in those republics to buy loyalty. You can find numbers in the USSR statistics. For example, USSR paid more for milk from farmers in Baltic republics than it cost in the grocery shops.
It was a big mistake to invest in those countries. Now they hate us the most despite all that effort and money poured there by Russia.
I don't think that major Ukrainian cities of let's say post-Stalin era were in worse shape then comparable Russian cities of the same time. You had more 'deficit' goods in Moscow sure, I don't know if Kyiv was lacking anything else to be honest.
Rural/urban gap was very real though but with each decade more and more people were able to live in the cities due to extensive housing program.
Around 1990-1991 there was a popular sentiment in Ukraine that we are feeding the whole Union etc, something similar was in Russia (that they subsidize other republics), the reality was a bit of a mixed bag
