Jonassj I don't know what keyboard would be good. Maybe something like [Login to see the link], but it doesn't support Swedish. It's possible the developer would add it, or if you know about android app development, you can make your own fork.
Kyocera phones are locked down a bunch. From what I've seen online, the only way people rooted is with one click root apps like Kingo Root. Some people said it worked, and some people were stuck with the Kingo Root app in their system partition forever (but root didn't work somehow). I don't know which Kyocera this was.
And while rooting does open up possibilities, I don't know if that would help you get Swedish.