Checks smart contracts being right or wrong?

The Ethereum virtual machine is a complex machine, nonetheless, it doesn't hinder the building of smart contract development.

What goes into the EVM are transactions that are carried out via a smart contract built through Solidity, Serpent, or Vyper. There are quite some other languages, the well known higher language is solidity.

About the right and wrong of smart contract?

No one particularly checks that in relation to the evm. What miners do is to check a transaction, having provided the transaaction fee?

What are transaction fee? This is a multiplication of the gas cost and gas price. The gas price fluctuates depending on the level of interaction on the evm. These miners check that a transaction provides the required gas fee to get it added to a block.

You should read about the block gas limit. Or, if there is time, do peruse the Ethereum Virtual Machine.

The aspect of miners validating transaction is not avoid adding transaction that do not meet the standard. The miners do a whole lot of work, trying to solve puzzles using computational resources.

Again, smart contract are not right, for me, if they have lapses that could bee hacked and the money exploited. This is what brings about hacks of defi companies; issues of security.

Also, you know what rug pulls are? I believe that's one of the problems of a smart contract that will define a wrong smart contract built to steal people's money.