Using Arduino for simultaneous lighting effects
Avoid delay() and use specific times of next actions and compare them to millis().  For a random time, set something like:

now=millis();
...
if(nextFlicker &lt; now) {
   toggleFlicker();
   nextFlicker=now+random(10000);
}
if(nextPulse &lt; now) {
   nextPulse=now+ isPulseOn? 100 : 1000 ;
   togglePulse();
}

...


If you are running more than the 50 day roll-over time of millis(), you may need some care to handle the overflows.  See http://playground.arduino.cc/Code/TimingRollover

For the strobing leds, investigate the timer-controlled outputs outputs.