Seems like someone has already done a full Dothraki memrise course
http://www.memrise.com/course/81961/dothraki-words/
http://www.memrise.com/course/81964/dothraki-words-by-part-of-speech/
Yeah, that'd be me and my brother. If you notice any errors, please send me a pm! 
Ya, I saw that you had contributed but I didn't recognize the other screenname.
I'm through the first 100 words and no mistakes yet that I have found. There might be some confusion with words like
mra which first appears as "out of" while it might be better known as "within". It depends on how well people know about the case assignment to notice the difference.
Nice to see you again by the way. You should stop by the chat and say hello to David some time. Though it's in the middle of the night for you as it is for me. The chats are on tuesday mornings at 4am CET. Though I'm not sure David was gonna make it this coming chat since he is at a convention in Seattle currently.