Or he could have used the chameleon arch and they could have withered and died together. Even when she's with him he's still the lonely god, she isn't enough even when she's saying she'll never leave him.

Multiple times? Apart from the Time Lord Lose Track of Time there's the 'oh, she knows' which could have been 'have a fantastic life' or 'I'm so sorry' or, knowing Ten, some complete random babble if he'd actually said it.