I've played Final Fantasy XIV with a controller since its original launch in 2010. Right now I use a PS4 controller connected to my PC either with a USB cable or through bluetooth.
So ultimately, my controller setup is the same as if I were on a PS4 with a usb keyboard plugged in. I would definitely recommend investing in a cheap USB keyboard for the PS4 to solve the typing issue. Granted, you'd probably need to be capable of typing while keeping your eyes on the screen, but the UI is rather nice in that if I'm attempting to type something mid-battle (as a healer) and someone takes a big hit, I can press O to back out of text input and react, and resume typing where I left off if another moment presents itself.
Alternatively, most boss battles are discussed before they're triggered, and I also see a lot of players (myself included) make macros for reminders of certain mechanics that are simply placed on the hotbar somewhere. Considering there's 8 different hotbar settings, 5 of which are static regardless of which class you're on (not even sure about turning on the extra set for holding L2 and R2 at the same time, might add even more static ones), you could easily set up macros for greetings, parting words, congratulations, apologies, mechanic reminders, and just about anything else. Obviously there's always going to be the occasional unique situation that isn't covered, but it would minimize your need to type while keeping you capable of communicating (and quickly).
