Can I ever stop using Tora

Yes you can!

Consider trying the japanese voice over with subtitles and/or adjusting the audio options to your likings otherwise in terms of volume. You can bench Tora in a later chapter as there will be a new driver that can fufill a tank role.

However there is a point in the game where the game subtly recommend you use Tora, but I found I didn't need to as I enjoyed being slightly overleveled just from playing the game and using rest experience at inns (this also helps as trash mobs many levels below you won't bother aggroing you).

I'll admit I've played most of the game (currently at chapter 8) with Tora benched as I don't want/enjoy grinding Tiger Tiger.

Edit: In discussion posts I've read elsewhere it is recommended that you use Tora as your tank for post end game content like superbosses. I had no trouble beating the main story with Tora benched though.