11. The Tenth Doctor's Timeline

Hmm, I’d always thought Death and the Queen belonged late in Series 4, as it’s a kind of faux departure story for Donna.

Billy Walker , gave your timeline a look and have a few suggestions-

The DWA comics with Heather and Wolfe might belong better somewhere between Journey’s End and Planet of the Dead. The Doctor doesn’t seem to have any reluctance to take on new companions, whereas by Planet of the Dead is in full ‘I travel alone’ mood, possibly brought on by what happened to Heather and Wolfie.

The Titan comics begin close to Planet of the Dead, as that’s what the writer said in media prior to it’s release and in the comic Gabby convinces the Doctor to let her travel with him by inadvertently him of the prophecy Carmen gave him (Carmen warns him about his song ending soon and something returning from the dark and knocking 4 times, Gabby cites a saying by her grandmother that ‘no song should end too soon’). 

The placement of Collision Course during Series 4 doesn’t quite work, as the Doctor seems to be travelling alone there. It could go in pretty much any period he’s alone. 

The e-book Keeping Up with the Joneses belongs shortly after Planet of the Dead, as Lady Christina is fresh in the Doctor’s memories. 

Made of Steel likely belongs between Lazarus Experiment and 42. Martha goes back to Royal Hope Hospital, where it’s seems like it’s been a few days (ish) since the events of Smith and Jones, whereas in The Lazarus Experiment she has the Doctor bring her back to Earth the morning after Smith and Jones. Also I think Martha remembers a mad scientist at one point (been a while since I last read it). It has to be before 42 though, as Martha doesn’t have a TARDIS key. 

You seem to be missing short story published on the Doctor Who website The Doctor on My Shoulder. This takes place right before The End of Time, as the Doctor mentions there’s something he’s been avoiding for a while and at the end as he’s leaving he resolves that ‘Time’s up’, kinda implying he’s decided to go to the Ood.

And, this a very niche one, you’re missing the short story A Dog’s Life. The story depicts the last few years of K-9 Mark III’s life, from his point of view, and ends with him being repaired by the Doctor in the cafe in School Reunion. K-9 recognises his master and it’s very cute. Actually come to the think of it, there might be a few more stories from that collection (The Doctor Who Files) that you’re missing, but I can’t remember enough about the rest (the K-9 and Dalek stories from that collection are the only ones which stuck in my memory). 

And more specifically between The Waters of Mars and The End of Time, as it’s implied he’s avoiding his summons to the Ood Sphere.

I have a feeling that the “one more party” is going to be the Tenth Doctor’s version of “Welp back to Amsterdam!”

I definitely think that the gap between The Waters of Mars and The End of Time is actually bizarrely one with quite a lot of potential as it’s effectively the Doctor saying F you to the universe and running from his destiny so really anything can happen. And it’s really ripe for exploring the Doctor's psyche following the Waters of Mars. I mean Out of Time already did a bit of that and it felt like a natural progression of what we saw on tv.

I wouldn’t mind them slotting a new companion into the gap. I imagine it’s going to happen eventually but it feels like the most natural gap to use for that, short of having a new companion travelling alongside a tv companion.