It depends a lot on the venue (whether there is a natural echo or delay from the ceiling and walls...), so would normally be dosed per venue. Be aware that, if there is speech between the songs, delay/reverb is rather more of a hindrance, so should be avoided at that time. Ideally, someone at the desk would be dosing any Fx in real time, but this relies on having a sound tech, preferably with knowledge of the repertoire. As usual, the standard advice of 'less is more' applies; better too little, usually, than too much. The answer, really, is 'a lemon : suck it and see'.
And 'No, it won't create the same Fx as the recording', but is that important..? If it is, play the recording and mime/lip-sync..!