my ideal version of new who canon goes something like:

the doctor never regrets ending the time war the way it did. not once. sure they’re remorseful, often guilty that they were the one who had to do it, definitely survivor’s guilt and a lot of the time they wish they could have been blown up right there with Gallifrey and the rest of the time lords. but given the chance to have a do over, they’d do it again. and again. they did what had to be done, and that’s the only way they cope with it.

(part of this might be informed by what happened to jamie and zoe, and the doctor never being able to forgive them for it)

the doctor never meddles with the time war, never even thinks about bringing Gallifrey back. eventually they come back anyway, which leads to Heaven Sent, which leads nicely into the doctor blowing up Gallifrey to hell all over again. There’s no part 2 to my favourite episode, no bargaining to bring Clara back from the dead, no weird power games with Rassilon, and absolutely no reveal about the Hybrid, no awfully long conversations with ashildr at the end of time, no memory wipe games. The Doctor just blows it the fuck away, which, tbh, is the only way season 9 should have ended. that finale is such a goddamn asspull. it’s like they expected everyone to forget that bringing the time lords back was 10’s worst fear, and the entire climax to their era was very literally Sending Them Back To Hell.