I added a few things to your mission. Mind you that all of it will work fine in SP. For MP you need to use a completely different setup. You will ahve to use addPublicVariableEventHandler and then publicVariabel in your trigger. I recomend not worrying about MP until you have the basics down in SP.
I basically just changed the marker text and color when the mission was complete, the task state as succeded, one trigger I used regular hint and the other I used taskhint.
there are numerous things you can add to make it nice looking.