User's text in my database as a separate table or within other data

Answer 1

This will depend:

You mention: "where kysymys is a question in English."

Are you planning to have the same question in other languages?

If that's the case, normalize the question and question body out to another table. That way, given a language and a question ID, you can retrieve the right one.

However, if the question is only going to be in English, just leave it in the same table. That's perfectly fine.

Answer 2

Are you planning to store revisions of a question ? e.g. StackOverflow allows you to revise the question text and it stores the history.

If this is the case I would store the text separately. You would store answers/comments referenced against the question-id, but the question text would be held in a separate table.

Your data neutralisation issue (above) is orthogonal to this (a separate issue of data sanitisation/cleansing).