I’m an iOS developer so I work on a Mac, but I still separated my work & personal tasks & notes. And I much prefer it this way. When I work I like to stay focused on work tasks, not be distracted by my personal goals and tasks. And when I look at my personal stuff, I don’t want to see some work project or task and get stressed out during my free time. 
So I use Things 3 for my personal tasks & the whole GTD system/routine. And Apple Notes for my personal stuff.
While for work - I use Obsidian, both for tasks & work notes. I really prefer having both tasks & notes in the same app for my dev work.
In Things 3 I have a similar setup to yours when it comes to Areas
These Areas of my life is where I devote my time in one way or another. They are pretty broad by design, because specifics might change. For example Discipline contains the tasks around the current GTD system that I use, with planning & reviews, journaling tasks and things like that. But in the future I might switch to a different strategy, instead of GTD. But Discipline will still be needed no matter the system I use. Or take the Adventure area. It is actually about my sailing tasks. But in the future I might buy a van instead of a sailboat. Or go backpacking. Culture is just books and my Spanish learning. But I might pick up piano lessons and study French later. And so on.
It’s interesting the order I arrived by in time. The bottom areas support the ones on top. But the ones on top are more meaningful/important to me. For example I don’t do Finance or Discipline tasks for their own sake, but because they allow me to do better in the other areas which are more meaningful to me.
I like to keep it simple as well. I usually use 2 weeks periods for planning and review. One week was too much overhead for me personally. While 3 weeks, or 1 month, I forgot/didn’t care about the tasks anymore. 2 weeks is the sweet spot for me.
The other levels beside the 2-weeks planning & review :.
- I started to be more disciplined by first setting a “Vision” - which basically just describes the areas which are important to me.
- Then I make 3 years plans. Just broad goals on the “direction” I want to take in the next 3 years. Not SMART goals, just big picture stuff like “I want to learn to play guitar” stuff.
- Then I make a 1 year plan which is a bit more actionable. Like I want to study guitar at least 3 days a week for the next year.
Being more disciplined has changed my life. I’ve been doing this for about 6 years now. And I have accomplished so, so many things I wanted for myself.
One more trick which I have discovered. When I start something new, I start small, really, really small. Just to get the habit going. For example I want to exercise daily. I will set a 10 minute daily routine. With stretches and some squats. And I’ll keep increasing the time or difficulty of the exercises every 2 weeks, 11 minutes, 12 etc.
At the beginning there is a lot of enthusiasm, and you want to start strong. But in time it WILL become an annoyance at one point. To get past that, it needs to be quick & easy. After a couple of months it will become a habit and it’s safe to keep increasing the time/difficulty of the task.
It’s like running a marathon. You can sprint at the beginning and it even feels good, but you won’t make it till the end.
