Your Twitch username, not the URL.
KapChat can fade out old chat lines.
The default time before a message fades is 30 seconds.
KapChat tries to hide bot activity by default. If you want to display bots, check the box above.
KapChat can prevent the clipping of chat lines, but it is disabled by default for performance reasons. If you have a large channel, you might not want to enable this.
You should choose a style that fits the game you're going to be playing. If you're an advanced user (meaning you know CSS), you can also choose to use "None" and style chat yourself. If you made a cool theme you'd like listed here, let us know.