An Open Letter to Chris Chibnall Concerning Doctor Who

Dear Mr. Chibnall,
I'm not going to mince words here, you have an uphill battle ahead of you. You've been given command of a sinking ship and asked to keep it going. This particular ship sprung a leak a while ago, but no one seems to have noticed or done anything about it, and now you're already halfway underwater.

But I want to help you. Doctor Who has weathered worse problems than this and a new Doctor is always an opportunity to win a new audience. Here's what I think you can do to get the show back to the basics that the fans know and love.

1. Full Time Companions: In Series 7, Mr. Moffat made the unusual decisions to have the companions go on short trips rather than a long one. Each week The Doctor picked them up, took them on an adventure, and dropped them off again. This has continued from the end of the Pond era all the way through Clara's entire tenure. It was an interesting break with the status quo, but it needs to stop now. It diffuses the tension as the companions are no longer homesick or wondering if they will ever go home. They don't have the problem of temporal displacement and disappearing for months or years at a time with their families wondering where they have gone. In short, they have no personal stakes. They live their lives during the week, and take their weekends in time and space. It's boring. For your new Doctor, have his/her companions be on the TARDIS most of the time. They should live there, like they're back backing through the vortex with no safety net of being able to go home at the end of the day. They should be on an adventure they think will never end. And on that note...
2. Short Term Companions: Don't have companions overstay their welcome. The Tennant era was marked with companions who only stayed 1 or 2 series while the Moffat era held all its companions for 2-2.5 series. That's too long and makes the audience too comfortable. Clara was the most egregious example of this as she had no personal story whatsoever in her final series. On top of that, before she left, she was so comfortable going on adventures, she was rarely scared of anything, which again, destroyed the tension. Don't be afraid to cut your companions after short periods. Heck, don't be afraid to have them leave unexpectedly mid-series. It will keep your audience on its toes and they will treasure the time they spend with the ones they like. It was also help to maintain the sense of wonder that the companions should have when traveling with The Doctor. 
3. More Running: The Tennant and Smith eras were both well know for the characters "doing an awful lot of running." Sadly, Capaldi has done more standing than running. I'm not sure if this is due to budget, Capaldi's age, or just a change in the direction, but it shouldn't become a trend. Running tells the audience there's some scary or urgent and keeps the energy up. If there are monsters about and the characters are just standing around, your audience won't take the threat seriously. You want them at the edge of their seat, not leaning back waiting for someone to eventually move. 
4. UNIT needs a new Brigadier: Again, it was an interesting idea making UNIT a more scientific organization, but it effectively neutered them dramatically. What made UNIT so great in the past was that it was a military organization that served as The Doctor's ally, but not his servant. They weren't afraid to charge in and neutralize a threat over The Doctor's objections. Right now, they're just a bunch of Doctor wannabe's who don't seem to know how to handle themselves without him there to hold their hand. I like Kate Stewart as a character, but she just doesn't have the chops to be the head of UNIT. We need a new equivalent of the Brigadier who isn't afraid to make his own calls and can disagree with The Doctor while still commanding his respect. I realize no one can replace Nicholas Courtney, but the new UNIT needs something more. 
5. Take a break from the Daleks: This one might put you in a tough spot with the BBC and the Terry Nation estate, but I think the franchise needs a break from the Daleks. Moffat once said that they become "the most defeatable villains of all time," and he's not far off the mark. Audiences don't shudder at the Daleks the way they once did. If anything, they fill like an obligatory once-per-series story point. If you can pull it off, I suggest you stop using the Daleks for a couple series. Let the audience miss them for a bit, then bring them back when you really need them. In the meantime, you can develop new villains and monsters. 
6. Last, but most importantly, keep it fun: On average, Capaldi's first two seasons were markedly more serious than any of the modern era. For many of the episodes, The Doctor's moments of levity were few and far between, instead of scattered regularly throughout. It wasn't until The Husbands of River Song did I feel there was a true return to form. Moral dilemmas are all well and good, but if you make them standard issue in every episode, you'll bore your audience. Please don't make this a sci-fi version of Broadchurch, where the comedy sometimes happens here and there. It should be a consistent fixture that's only shed in the most dire of moments. Remember, your audience wants to laugh and cheer as well as cry. 

Whether The Doctor is a man or woman, whether he has his TARDIS and screwdriver, or not, this list is what I feel you and your writers will need to revive the flagging series. Taking risks is always welcome, but it requires the wherewithal to know when something isn't working and change course.  

Good luck Mr. Chibnall. We're all counting on you.