Padawan's not too bad; it just... reminds me of younglings too much. You know that kind of "space language" that Lucas actually averted pretty well in the original films that seems to just stick out much more in the prequels. Its not like we had fancy names for "Knight" or "Master" after all. Its a minor pet peeve.

Language in regards to the Jedi is tricky because you run into the obvious problem of why such terms are not brought up again. I do think it can be done, but one has to be careful with it. The Darth thing is intriguing though, as I've had similar thoughts regarding terms of that and "sith" to describe not people but concepts. Anakin using the Darth name as a figurative f*** you to the Jedi and his old life and an acknowledgement of how his old name and life has no meaning anymore would be very interesting to watch, especially if its part of a greater plot line of him seeing the dark side as stronger and more adept towards his goals.