Hate to be the fly in the karaoke ointment, but:
Since you mentioned karaoke DISCS, I'm happy to help.
The mixer is fine for DJ work, but doesn't cut it for karaoke. Things to remember:
A) Despite SOME similar equipment, the skills and equipment of a Karaoke Host differ extremely with that of a DJ.
First of all, in Karaoke midrange is king. That's where the most important part-the vocals- are for karaoke. That's also where you will have to do the most mixing. Your mixer will require all the normal effects ( echo, delay, pitch change, etc) as well as DIGITAL KEYCHANGE for the music, because many try to sing songs "not quite" in their range.
B) Keep in mind that a DJ actually works with pre-mixed music- pro musicians playing music for a specific professional singer in their key and to writer specs. Though a DJ may add a few effects, the work as far as SOUND is pretty much already done.
With karaoke, you are working with studio musicians creations of "sound alike" music ( all of which differs from producer to producer) and a new and amateur singer each and every time. In other words, you must mix amateur vocals and changeable music tracks "on the fly" ( you have have about 5 seconds per singer to do it right). If you don't have the skills, I'll tell you straight out to skip karaoke and build your DJ skills- THEN try something new.
I might add that Karaoke Hosts require stronger interpersonal skills than DJs. If you have them-great! If not.....more work.