When Sylvia is mentioning the photocopying job to Donna in the first flashback, she says "He [Jival Chowdry] runs that little photocopying business and it needs a secretary." But later, when Donna is preventing her past self from turning right, she says "He runs that little photocopying business in Merchant Street, and it needs a secretary."
When Donna is being shown the time beetle in the mirrors, the position of Rose in the background flips from facing left to facing right.
If the 10th Doctor had died in The Runaway Bride (2006), as a time traveller, the previous 9 (or even the 10th) incarnations would have saved the Earth from all the threats featured.
No, if they were going to do that they would have done so anyway, they were in his past.
No, if they were going to do that they would have done so anyway, they were in his past.
In a world where The Doctor died in The Runaway Bride (2006), he wouldn't have gone back in time to AD 79 (see The Fires of Pompeii (2008)). The Pyroviles would have turned the entire population of Earth into molten rock monster aliens, erasing all history after AD 79, including Donna's entire world.