I'm a fan of most of this advice here. Also, as someone with ADHD, I'd also add to this advice some concrete suggestions that have been very helpful for me.

Regarding Point 1 & 4) As someone who's a been following the health podcast space of researchers, I've been finding that exercise, nutrition, and sleep are the foundations that are critical to feeling one's best. However, like all things, the devil's in the details and finding a protocol that's sustainable, affordable, and palatale is pretty key to being compliant and feeling one's best.

Personally, my goals nutritionally has been to just "feel better." I noticed very early on in life, that almost any meal I consumed would lead me to falling asleep and being unfunctional for 2-3 hours in a state of brain fog. No amount of caffiene and such could really snap me out of it. So I went to the doctor and got prescriptions for stimulants, but they mostly have diminishing returns and have other downsides. And my whole life, I've always had a slight bit of fatigue, a bit of ADHD, a bit of narcolepsy, so I feel like there's so much more on the table that I could engage in, but have failed to really get at. So I've found that really getting my diet in order has been key. Now that I've embarked on on a multi-year journey of nutrition and fitness, I'm finding that I have a ton more energy to engage, a lot more focus (still hard, but much easier) and I have a lot more mental stamina than I used to have.

I've given my protocol to several friends, and not one person hasn't felt better on it so far, even if they didn't integrate the exercise portion. I've also read numerous change-your-life-by-doctor-foo books and they generally all come to the same conclusion: the body is a chemical reaction machine and it needs the right set of molecules (either via gthe gut microbiome (bacteria) or synthesis or nutrition) to function at its best. And at the core of everything health, optimizing mitochondrial function is at the heart of all things health, for just about every curable/manageable ailment and chronic health condition out there. Food, as personal and opinionated as it is, is one of the core tenets for functioning well. And in that context, it becomes obvious that reducing or eliminating the bad, while increasing the good is the key to many improvements.

On the food front, it's too difficult and not practical to really cut out everything, but I do agree with cutting out most "ultraprocessed" food. (ie chips, soda). Since getting healthier, I find that my body can tolerate junk food far better than it ever has been able to. So much so that, if I go on vacation with friends and binge on junk food for a week, I'm fine. Over time, I noticed that my tolerance for the "bad" stuff grew more and more. For OP, I'm sure on your journey, you'll experience similarly.

What I find that most people have difficulty with is getting enough of the good stuff. Most of the compiled research out there recommends some form of eat lots of whole foods, lots of color, lots of variety, and I've found that getting enough in quantity and variety is tough.

In an ideal world, look towards getting 2-3 cups of color, 2-3 cups of greens, and 2-3 cups of sulfur per day. This is easiest done with a smoothie and drinking whole foods. Then my daily food intake becomes about getting healthy enough amounts of calories of proteins, carbs, and fats. Generally, a target of around 50-75% of 1g per lb for protein gets most people to a solid target for muscle building and retention. Then most folks can mix/match how much in carbs and fats they want to target. For most, what that balance is, doesn't really matter, unless one has a higher propensity for diabetes and should keep their carbohydrate targets relatively low. I've found that the best way to address all my micro-nutritional needs is to make batches of smoothies 1-2x/week and consume them on the go.

My smoothie concoction is as follows: 3x batches in a 64oz Vitamix (don't bother with the smaller vitamix and cheaper blender alternatives. They aren't powerful enough). This fills 6x 28oz blender bottles, and I look towards drinking 2x bottles/day, usually for breakfast and a mid-day snack.

Smoothie mix: 24 oz colorful grape tomatoes (color), 16 oz carrots (color), 3-4 heaping cups frozen blueberries (color), 12oz brocolli (sulfur), 16oz greens mix (greens: spinach, chard, kale), 3x apples, water.

On the supplement front, most people don't get enough sun (vitamin D) and Omega 3's (fish/algae), so I supplement about 5000IUs of D, 1-2g each of DHA & EPA for the antioxidant effects. Lastly, I think which is super critical, mitochondrial health is important (especially cuz my family has a history of diabetes) So I also add about 200-300mg of Ubiquinol (Coq10 in reduced form), B1 as Benfotiamine (dosing per label) and 5g of creatine for its mitochondrial benefits. For most of the general public, I would say this addresses most of the deficiencies that exist in the standard american diet. It addresses comments like, "80% of the US population is vitamin D deficient, omega3 deficient, etc"

Regarding Point 6) Research has also shown that doing something like 10x body weight squats around once every 45-60 minutes while sitting down also has incredible benefits, even if one isn't able to make it out for a walk. Just wanted to point out that there are many alternatives to movements and many benefits don't necessarily need to be super strenuous.

Good luck OP!