I followed the same flow for learning Spanish as you, and your site looks excellent. I too have a bunch of infinitives memorized via Anki, but would like to practice all forms of conjugation, and manually creating more flashcards is simply too labor-intensive.

One thing I'd like to see is the flashcard interface translated to Spanish. I learned Spanish in Spanish, for the most part, and I get confused when I see "imperfect" and I have to remember that it's really what I learned as "pasado/preterito imperfecto." Built-in pronunciation via TTS would also rock! One could probably write a userscript to do this, but it's always nicer to be built in.