Mike, your "I have learnt that" section summarises DSO work quite well. Its a stark contrast to planetary imaging. Once you get the basics down, you can begin to refine how you collect data and more importantly how you process it - which is actually where 80% of the work resides.
Well done on the milestone. Only up from here. You do realise that as you progress, you raise the stakes. Thus, everyone will expect more from you (or at least I will anyway

).