Dont give up.
I assume that since you have 5 dps you have no trouble transitioning from heavensfall with 1 ghost.
For thunder/dynamo Nael will jump on the person who ran out with the fire out so dont run too far, and what we do is position thunder behind the boss and rest of the raid in front, you can start to position right after he jumps.
For DBs with double streams just spread around the center when the first DB mark comes up, do it in advance and start pre-healing.