Hi Motanum,
As Martin correctly mentioned, a Sequence node will run through each event without delay. Your solution will work for you in this case, but be aware when using a Sequence that a delay will only delay what follows it in event, but will not delay next event from firing. So in example above, you have a delay at beginning of your second event, which will delay door opening nodes, but Play node in third event will fire before delay has finished and thus before door opening begins. Generally, if you need events to follow each other with any sort of passage of time, you should link them all together in same event. Sequence will fire each event virtually simultaneously.