As far as I am aware, it is impossible to delete a transaction you have sent. Doing so would require deleting the transaction from the Bitcoin blockchain.
Even though the current status of the TXs is "Pending", both have been sent. Both TXs now need some more confirmations from other Bitcoin clients before they appear as validated on Electrum.
Nope, you are wrong.
Tx can be deleted as long as its not confirmed.
Pending transaction = pending for broadcast on network.
If you check my blockchain link of that 0.315 transaction, you will get error now.
Because one of the input of that transaction was a tiny dust amount from a faucet and was probably sent via blockchain.info (api). After 2 days blockchain.info stopped broadcasting that uncofirmed transaction and rest 2 transaction became invalid and got removed automatically.