Will you support forks or I need to withdraw my ETH to get ETH forks?
I’m not aware of any proposals to modify the protocol in response to the merge. Any such proposals would be discussed on this forum well beforehand.
Assuming there are no changes to the protocol, in principle it should be possible for you to withdraw the forked ETH from the cETH contract on the fork. However, there are reasons to anticipate that bots may endeavor to borrow all of the forked ETH in the protocol immediately after the fork, which would make it impossible for you to withdraw your ETH.
I’d recommend reading up more on the potential risks of money market protocols on forks that preserve state, and then making your own decision about whether you should make any changes to your position before any potential fork.