Settled down with Lelouch after 1000+ years of partying and fucking all around the world

Did you not watch the movie?

Not canon

Shirley was the only girl he kissed back

A person who kills a Code user with a fully developed Geass becomes a Code user. Lelouch killed Charles (Code user) when activating his double Geass. When he dies, Nunnally can see his past when she touches his hand. We only ever see this happen with C.C. Because she's a Code user.
Lelouch was immortal and that's why C.C. says not all Geass users end up alone. "isn't that right, Lelouch?".
He was the guy driving. End of the story.

Why is he still able to use his Geass? How can you confirm that Nunally actually saw those things and it wasn't just a moontage for the viewers? Why did the writers confirmed he died and made the movies, explicitly stating there were an AU

wanting virgins is a virgin cope
>he's never banged a girl with BPD coked off her tits

>Why is he still able to use his Geass?
That's a very easy answer. Because the Code activated when he died for the first time.
Remember Charles? Lelouch used his Geass on him and he shot himself, just like Lelouch ordered (if he had the Code at this point this shouldn't be possible because Code users are immune to Geass). But right after that he stands up and we see the Code on his hand. The Code and immortality activates once you die, not right after killing a Code user. The Charles scene confirms it. C.C. was bleeding and about to die when she killed the nun too. Hell, she even supresses her own Code at one point. But that doesn't solve the immortality problem. Why? Because it'd activate regardless upon dying.
tl:dr Code activated when Suzaku stabbed him, not beforehand
>How can you confirm that Nunally actually saw those things and it wasn't just a moontage for the viewers?
How can you confirm she didn't? All those memories she never saw appear right after she touches his hand and she looks surprised. Like she suddenly had an epiphany about the whole thing.
>Why did the writers confirmed he died and made the movies, explicitly stating there were an AU
The writers never confirmed he died though. They said they wanted an open ending and refused to answer
The movies take place in an AU because there was no time to adapt certain arcs so they removed the storylines completely. Don't see how this is related to Lelouch in any way. Him being alive in an AU doesn't mean he isn't alive in the canon timeline. They're not mutually exclusive.

>Why did Lelouch choose her over all the other virgin girls?
Because C.C. is the only one who's an intellectual equal to Lelouch really.

>Not canon
It's the new canon so get over it.

>Bro the non canon movie totally proves my head canon
Cope

>How can you confirm she didn't?
Not the same user, but I think I remember reading once that it was said by the directors that it was just visual metaphor for the viewers and that Nunnally simply put the pieces together on her own once she saw the smile on Lelouch's face and held his hand. Need to find the interview for that though so take it with a grain of salt.

>The writers never confirmed he died though.
But he did. It's exactly the reason why they felt the need to create a new AU with Resurrection. Even in the manga adaptation of the former that is set within the TV timeline shows that Lelouch died that day too.

I'll have to rewatch the Nun scene to confirm your first point.
>How can you confirm she didn't? All those memories she never saw appear right after she touches his hand and she looks surprised. Like she suddenly had an epiphany about the whole thing.
Because anyone who knew who he was figured out what he was trying to do. Kaguya and Kallen had the same realization and they didn't touch. This is by far your weakest point and a reach.
>The writers never confirmed he died though. They said they wanted an open ending and refused to answer
Okay so it's just as likely that died since they left it open to interpretation.