1. Have one last event -- let's call it the After Death Event -- whereby Death becomes permanent and for ever. The point of the After Death Event, of course, is to encourage writers to seriously think about how they resolve their plots without always turning to death as a gimmick. It will also encourage editors to use their veto powers more when it comes to death in general. Let's give back death the gravity and finality that it deserves.
2. Following "After Death," or perhaps during the event, transform or depower most, if not all, all the multiple Thors, multiple Hulks, etc., that exist presently. That's right, I'm going straight Highlander on their butts: "There can only be one." Now, I may stretch it to one male version, and one female version, but that's it. Marvel needs to stop diluting the brands of their top characters.
3. Officially establish that Jean Grey is the one and only true Phoenix. Sometimes, she chooses to forget who/what she is. Jean is not merely a host for the Phoenix Force, nor is the Phoenix Force some cosmic abstract that exists apart from her. The two are one and the same being, made manifest by the Creator a billion-billion universes ago. When Galactus was lying in his cosmic egg, it was a young Jean that was singing him lullabies and rocking him to sleep.
Jean is THE Phoenix, one of only a handful of beings that exist outside of Death's prerogatives. This fact would be made apparent in the "After Death" event. At some point Death and its cohorts will think that it has won the day. But out of nothing Jean Grey will spontaneously generate, undoing what Death had wrought. The Phoenix always rises.
Lastly, to help keep things simple, I would establish that anyone else that had supposedly wielded the Phoenix Force were sadly deluded. They were not tapping the Phoenix Force, but rather linking into residual energies of the Chaos Bringer that had been dispersed to the Astral Plane by Professor X back in the classic X-Men 136. That includes Rachel, Hope, Cyclops, Namor, Emma, Quire, Giraud of the 31st century, Stepfords, etc., etc. While bestowing Phoenix-like powers, the Astral Plane sentience is but a glamour of the Phoenix and is nowhere near as powerful as the one true Phoenix. (Yet another point that would be made clear in "After Death" as Death is going to make the faux Phoenix hosts -- past, present and future -- one of its first targets.)
4. Have multiple artists work simultaneously on books the same way that multiple artists work on animated features. I'm still seeing way too much crappy artwork by individual artists, which wouldn't happen if you had a team of artists working together. The team would develop a consistent rendering style and standard and hold one another accountable. I also think that you could get books out the door much quicker.
5. Bring back Marvel Spotlight/Presents with a focus on heroes and teams that have been in limbo for more than a year.
6. Bring back Marvel Premiere and feature story arcs for relatively new characters to the Marvel continuum. Like Blue Marvel.
7. Start a new series titled Marvel Comics: The Book of Infamy which features stories about Marvel's villains, new and old.
8. Continue diversity initiatives with emphasis on the global community, so that the next time that I go to an Avengers movie I won't hear a little Asian kid ask his parents if there are any Avengers (that look) like him.
9. I sit down with a panel to determine who the 10 most powerful/influential/best in their respective category heroes are in the Marvel Universe. If a preponderance of the results are men, I introduce a corresponding number of new female characters (or elevate existing female characters) to this upper echelon. If a preponderance of the results favor one ethnicity in appearance, I order the creative teams to develop or elevate a corresponding number of diverse characters for this upper echelon. Not quota, just quorum.
10. I bring back Alpha Flight for a 24 part series. After a major foul up, the new Canadian regime revokes the team's mandate to operate domestically. In lieu of outright disbandment, the Canadian government sends Alpha as part of a goodwill pact to Australia for a year, hoping the uproar over their failed activities dies down. Australia, of course, is all too happy to have them. Alpha Flight is welcomed like rock stars! But the fun and games don't last, as an old and very powerful villain re-emerges.