MAC Book OS High Sierra 10.13.4
That is your issue right there. Every new OS comes with issues, and we are waiting for OB 1.2 that has the fix for the new USB drivers in High Sierra. I find that my AR MKi bends occasionally with just the USB plugged in, without playing it through Ableton.
Also, I upgraded to Live 10 and the reliability has increased slightly. If you have $80 and are looking for marginal improvement, the intro version of Ableton 10 wouldn’t be a bad thing to have for your show (though I don’t know how many native instruments you use). This might have mixed results at the moment though, as there is variance across systems. But going forward (especially OB 1.2 release) having updated software should alleviate certain issues, as developers always try to use the latest version.
In all honesty, OB doesn’t currently stand up to “mission critical” uses. You might be better off finding an analog mixer and some cables if you want to sleep well the night before your show.
Related link (issues with Sierra late in 2016):