Using selfdestruct(beneficiary) with the beneficiary being a contract without a payable fallback function:

will throw an exception, because the fallback function is non-payable and thus cannot receive ether.

it's impossible to secure a contract against receiving ether, because selfdestruct will always send ether to the address in the argument. This is a design decision of the Ethereum platform.

selfdestruct doesn't send anything to a contract, it just re-assigns the owner of the contract to a new person. Sending ether must be done outside of selfdestruct.