Lol, no, you can't control what is being set or what modes are happening at the time that your ascii art is playing. All you can do is ask people to be quiet when your ascii is sending to the channel.
Btw the only thing you could do in your case, is to use a timer, that will trigger 2 seconds or x seconds after joining the channel. That way, atleast the auto oping and stuff won't interfere, but there's nothing you can do about other people messaging things, or setting modes.
on me:*:JOIN:#GGGGGGGGGG,#channel,#ect: timer 1 2 play # ascii.txt