There is an ICO that asks for ethereum keystore file, which is unusual for me as far as ICOs go. Even though it does not looks like it contains private key and password it still feels unsettling. Is it not private, can it be shared safely?
You should definitely not give away your keystore file as it contains your encrypted private key. The only thing that can decrypt your private key is your password. However, one could perform a brute force algorithm on your keystore file in an attempt to crack your password and gain access to all your funds.
If you create a new wallet on myetherwallet.com it explicitly states that you should not share your keystore file.