What is missing from my garden soil?

Looking at what you have said it seems you should have a super garden but if you don't I have solved the problem with mulch. Seriously all those amendments etc are best served to the plants under the cool shade of a mulch. Especially where you have a walkway between the rows. It doesn't even have to be a super good rich composting mulch just a good covering will be a boon to your plants. I have planted and fertilized some very dismal gardens then one year I was going away for over a month so I just mulched to see if I would be able to salvage something when I got back. Wow did I get a lesson on how much care a plant needs I would have to stand out in the sun and shade the soil all day every day or hire some cheap mulch to do the work, The mulch I used was from a shredder and was made up of wood chips and junk vegetation but the results made me a true believer in mulch.