Good. Cheap labor

The ones quoted here are either Ukrainian or Russian opposition websites.

So why then Ukraine hasn't built anything since the fall of the ussr?

Who said anything about theft?

Paper economy

And Europe is a paper mouse

The whole world watches American movies and listens to American songs. Don't you know that?

There would be a second Chernobyl in Ukraine now if Ukraine hadn't given up their nuclear weapons. The warheads has an expiration date. Ukraine's soviet warheads would have been expired long time ago. And Ukraine doesn't have technology to dispose of them

Russia does not rely on Ukraine to manufacture its rockets and the engines for Russia's ships. Ukraine stopped cooperation with Russia on space after 2014. Ukraine stopped manufacturing Zenit rockets in 2014. Russia has other rockets which are built in Russia

There is also Lev Pontryagin (1908-1988, born in Moscow). A Russian mathematician. Pontryagin's maximum principle is used for solution of topical problems of spacecraft motion control.

You are responding to Ukrainian propaganda. Don't take it seriously

This is the kind of propaganda that the Ukrainians have been fed since their independence in 1991. To summarize it: it says that everything good were made by Ukrainians in the USSR, and also trying to demean Russia. Some combination of delusion of grandeur combined with victim complex. And all that while Ukraine was doing worst among other former soviet states. They fucked up everything. They had aviation industry, space industry, shipbuilding industry -- they had inherited all that from the USSR. Nothing left. Everything decayed and disappeared even before the war.

Prime example of a Ukrainian nazi

There is a lot of phone scam that target the Russians. And often the scammers use calls via WhatsApp and Telegram.
As for "sabotage" - yes, your beloved Ukraine use scammers to involve the Russians in sabotage. First, they scam people out of all their savings then they say "we will return your money if you do this and that".
The phone scam that target the Russians has been going on for years and the scammers are mostly located in Ukraine. And it started years before the war.

They are not illegal. Your laws are not world's laws