Are there DEX, where it is possible to change "coins" that are not tokens, but have there own blockchain. Or can we only change "coins" with a DEX, that are part of the same blockchain and are tokens?
There are only a few real DEX exchanges that are not using tokens, and best of them is certainly Bisq.
Bisq suppoorts Monero (with highest volume) fiat currencies, and few more altcoins, but best thing about it that it doesn't need any kyc verification.
For monero to bitcoin there is also Atomic swaps, and that you can find other wallets supporting atomic swaps like Liquality extension but it works only for Bitcoin and ethereum.
A) Are there DEX, where I can change BTC against Monero (I mean not tokens, but the real BTC and Monero)?
B) Or can I only do this on CEX?
C) Or are there "copys" of Bitcoin and Monero for example Ethereum, so that I can change Bitcoin tokens and Monero tokens on (for example) Ethereum chain?
A) Bisq and unstoppableswap.net
C) I don't know and I would never do this, especially not for Bitcoin.
Safepal wallet app allows users to swap coins between different blockchains (real coins).
This is not Dex exchange, Safepal is using Binance exchange for swapping coins from different blockchain, and it's not even supporting Monero.
Or do I miss anything?
Coimarketcrap is owned by Binance so they won't add Bisq, and it's better that way.
Bisq has it's own markets page:
https://bisq.markets/