I don't think so. Electrum wallet has a feature that places a timelock.
On transactions,
not on addresses.
Cannot someone send money to the merchant's address with a vicious timelock that the merchant may not be able to spend it this life?
Not possible.
If I create a timelocked transaction which cannot be spent for 100 years, then I won't be able to broadcast that transfer since all nodes will reject it until after the timelock has expired. The transaction won't be accepted to the mempool, so the transaction won't even show up as unconfirmed (let alone as confirmed) - it will simply be rejected as invalid. As far as the merchant is concerned, you haven't paid and so they won't release the goods.