Sounds like you're getting there! If nitrates are rising and the other two are stable then I'd say it's time for fish!
For food, I used marine cuisine for a while, but then started making my own by mixing seafood in a food processor. More upfront cost, but more cost effective. In a pinch, I feed formula two pellets and formula one flakes.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef