The devil is in the details, and I have never done a project like this. I ignored in the first response what the final output will be: burned in? embedded as closed captions? or sidecars that are selectable? The is important for any issues with fonts/language characters.
> This script will be send to the countries to make the translation in their language.
And because only they know the specifics of the technique that is talked about.
So forget the auto-translation. This will be simpler and higher quality.
If you start with an initial srt in English that is timed, the question is what is the easiest way to create translation srts. If the translation personnel are good technically, I'd be tempted to let them edit an srt (text editor). I would not use PR, in part to avoid problems that occur if you "duplicate" a caption stream inside PR. (You can avoid that copying/renaming outside PR and import individual files for each language.) PR is also limited on style support for srt's.