Hard to see the hot pixels and stacking artifacts at that size so just some general thoughts... are you dithering? If not, that should give you a big improvement in quality. Other things to look at are whether your calibration process needs tweaking, whether you have enough subs and experiment with rejection algorithms and parameters to get a cleaner result.
I'm certainly no expert but a close inspection of these so called hot pixels reveals they are stacking artifacts. You will see a repeating pattern of 2 red dots above 2 closer green dots. Almost as though some stars did not get aligned properly. Strange that it is not global. I agree with Rick, go back to the stacking phase and change some attributes and settings.
You should also try to remove the gradient bright area on the right side of the image if you can. Great colour though.
Median combine will give you lower SNR than average combine by about 20% so it may be worth persisting with average and tuning the rejection algorithm and parameters.
If all else fails, zoom in and pick them off manually in photoshop. Despite all the best calibration these things happen and it's no big deal to spend 10 minutes and clean up the stragglers Really great images!
loads of detail, well done 
