Hey there! Welcome to AFN
Ive been growing for about a year and have recently switched over to organics so I might be able to help out with some of the questions you had on the specifics.
You're definitely on the right track and have done your research. One thing I noticed is you were going to layer your soil. I would recommend against that as it can cause a range of issues with your plants roots. It's better to just mix it all in together.
I pH my water each time to 6.3-6.5. I use RO water with about 100ppms of calimagic, some hydroguard and some yucca. I found that input water can cause a lot of issues and my local water is terrible which is why I do that. My plants get recharge once a week and then a dose of bud candy in the last 2 weeks of flower. Other than that just pH'd water.
As far as nutrients go the CoM should be good, I have never used it but I have heard of others using it and having good luck. I use Down to Earth personally but either should work great. My plants get a weekly top dress after my fox farm ocean forest runs out at about day 25.
If you're worried about any deficiencies you can pick up a few things to have just in case. Bone meal in particular is great for P deficiencies. I ran into that with nearly all of my original plants and was the one thing I wish I had gotten earlier. I also had issues later on with calcium deficiencies, some Dolomite lime or calmag will handle that. Blood meal for FAST doses of N, kelp meal for K, lime and Epsom salts or Cal/Mag for calcium and magnesium. It's not a bad idea to have some worm castings to mix in with your dry top dress. You can just use some extra soil as well.
Here is a link to my current grow if you wanted some more specific information. Don't hesitate to reach out if you have any questions