I’m thinking of calling my earlier mentioned edit The Dalek’s Master Plan: Regeneration Edition. Here’s how I think it would go (there were some errors and less details in my last rundown):

The Myth Makers but Katarina doesn’t join
The Massacre but without the Doctor’s Speech or Steven’s false departure
All the Steven and Dodo stories unaltered up until…
The Savages but without Steven’s actual departure
The Daleks’ Mater Plan 1-6 with Dodo in place of Katarina
The War Machines/The Feast of Steven mashup but with Steven’s departure from the Massacre and, get this, Dodo as the hallucination of a guilt-ridden Doctor (she’s in non-missing episodes so this is probably only the only feasible way to account for her death but it works out nicely)
The Smugglers unaltered (if you really wanna watch it)
The Tenth Planet without the regeneration or hints thereof and with Steven’s return from The Massacre
The Daleks’ Master Plan 8-12 with:
- Ben and Polly added to the cast (not sure what I’ll do about the one non-missing episode)
- Mavic Chen revealing himself to be the Master (a headcanon of mine that works nicely with and was indeed spawned from the story’s title)
- Steven’s departure from The Massacre
- The Doctor’s speech from The Massacre (not sure I’ll deal with Ben and Polly being around when he says “They’re all gone now”)
- The Doctor’s regeneration from The Tenth Planet (now with color regeneration energy)