Better filtering (if a value has been changed during upgrade or not / if a value hasn't been changed at all during upgrade / if a phrase has been added during upgrade / if a phrase has been changed at all from its initial value) - rephrased below,
Removing deprecated phrases / unnecessary phrases - can save some resources,
3rd form gender support - getting the gender of a user who made an action, something like this: Dan commented on your thread. Dan = 3rd person. If you have questions about the 3rd form gender, please let me know. It's a crucial improvement not just for me, but for other languages like spanish I think that arabic too, and a few other languages as well.
I hope you'll consider these requests seriously and positively. I think that once that these will be implemented, things will be easier with internationalization.
Thank you for your time.