Board Thread:Suggestions forum/@comment-27170788-20160419032145/@comment-25101690-20160426222456

And about editing the speech files:

It's easy and unproblematic to edit a single line of text from these files. This won't mess up anything. For that, you have to unzip the mod file, find and open the text file, edit and save it, then zip it again just like it was before.

When adding new lines or editing lines, you have to take care of the control characters (I think it's percent symbols followed by a letter: "%s"), but it's not a big problem either.

I'm confident that it's possible to change speech files with resource packs, but it's too long ago that I tested it and I might be wrong.