Is that true that we have to move all our coins to a bitcoin core wallet so that in case of a fork to Bitcoin ulimited we have our coins also there? I heard that it is not good to leave the BTC at exchanges because they won't deposit these BTU 1:1 to BTC. Anyone knows more?
Here is my opinion. To get your BTU you must move or keep your bitcoin on the direct wallet which means you're using the software wallet. BTU will be running on the different chain or in this time I will be believing about the forked chain from the original bitcoin itself. So, you must wait until the forked chain will be fully activated. And the bitcoin unlimited dev will make an announcement or a method for you to get your Bitcoin unlimited.
About the distribution of the bitcoin unlimited by the exchange site is depending on the exchange site itself. I think they will try to distribute the bitcoin unlimited coin with same equal to the original bitcoin.
If you're having 2 bitcoin on the bitfinex wallet and you will get 2 bitcoin unlimited and you can manage it on the token manager. I think you must read the bitfinex announcement and it's a reliable source for you.