Welcome to NGA, Andrew.
I'm perhaps the last person to ask about growing vegetables. Other than growing heirloom garlics for years successfully, I can't say that I have any expertise whatsoever. OK, I've grown tomatoes for years too, and am even growing them here in Vero Beach (sort of) successfully, but I would not say that constitutes much knowledge about growing them.
Andrew, one thing that I am a strong believer in is rich, organic, well-draining soil, whether it is garden soil or potting soil. I custom-make all my own potting soils, even orchid media, and amend my soil when putting something in the ground. I use coir-based media seldom, and when I do, it is mainly going to be a coir medium especially made to germinate seeds.
Even with my rich potting soils, I still use fertilizer. When it comes to tomatoes, I use specific tomato fertilizer, something that not only feeds the plants but also helps prevent blossom end-rot. Also, my vegetables get full sun, from dawn till dusk.