Will someone have access to your wallet without your device but the person manages to see your private keys and copy them without your knowledge? Will the person be able to withdraw your money or change your password and block you from having access to your wallet?
Yes, someone can move away your fund in your wallet if that person gets access to your private key or your seed phrase, that's why it's always advised not to share your private key or seed phrase with anyone o in the process of creating your crypto wallet. The person that gets access to your wallet doesn't need to block you from accessing your wallet because he only came for your fund.