Hi DJ A.S.,
XLR connectors is another type of connector. Easy plug in & out style and you don't need to worry too much about how you treat them. Your controller has XLR output so will be easy to plug in XLR cables in the club.
You can read about headroom level on ITCH manual (Link:
serato.com)
Quote:
Headroom
Select how much headroom your device has before the internal limiter engages.
Less headroom results in louder output, but has a higher chance of the limiter engaging, especially when more than one audio channels are in the mix. With the initial headroom setting of 0dB you can apply 3dB of gain per deck before you hit the limiter.
You can use ether stereo or mono. Either-way you can here music from speakers. I suggest you to ask sound guy in the club if you can because of it is very depends on their setups. Usually "stereo" only works on 2 speakers. (Left & Right)
You can check out your controllers firmware version on your ITCH setup screen. If it's not up to date then you can download and install from their website.
Hope this clears things up for you.
Thanks
Rui