yep, you can use Choli's translator to see missing keys and depricted keys...
For ampersand collisions, you need to check everything manually.
EDIT:
Choli's Translator (standalone):
Messenger Plus! Translator
This was made for the old translation files of Plus!, but it works just as good for the new files. The only thing you need to do extra is entering "*.*" in the file select dialog to select the proper files (since they are now named a bit differently). See the thread for more info regarding this.
Choli's Translator (script version):
[release] Messenger Plus! Live Translator
Though this is still somewhat in beta-stage
/ 
