Linking to bnet is used mainly for public profiles… which aren’t being used much at the moment.
We used to have a list of characters from your linked battle.net accounts… but I think we didn’t add it in the UI redesign. We’ll give it some thought as we work on future UI updates.
I know that on my android devices, if you long-touch a letter on the keyboard, it pops up alternative versions of a letter, e.g. with an accent, etc. Not sure if that works on the kindle as well.