I had a similar language recently... I was kinda interested in the whole language evolution thing, so I researched dictionary.com and Wiktionary for French and Spanish etymologies and then completely screwed up the Latin roots into its own language. It was fun. I figured out, finally, how "lūpus" turned into "loup" and "lobo" after so many years of mind blowedness upon thought of Latin evolution.
Oddly enough, I kept three cases as well, although mine were the nominative, genitive, and dative. Did you have any specific reason to leave in the cases that you did?
Also, could you put up some examples? I'd really like to compare my language to yours... I think it'd be really interesting to see how we thought things through.
Fluent: English, русский язык
Proficient: français, 日本語
Beginning: suomi, davvisámegiella, 中文 (普通話), norsk, cymraeg