The first image is very nice compared to the second two, I am sucker for natural colours. The more subs you can take the better detail you will get out of the nebulosity and greater clarity throughout the image. You are having to over stretch the data presently, getting a lot more extra subs will make your image pop
The final image has gone a little fuzzy, the first one had more clarity. Processing data is hard and there is so much auto tooling out there that can cost a large amount of money.
I found them confusing, most having a large complex learning curve and I know my way around computers. I personally stick to the basics, DSS and Photoshop, simple but I can still get great results.