Yeah definitely , sometimes I mess around with some of my astro shots a bit , and yeah somtimes it's hard to get the balance right (of course I could probably use a bit more practice on that front :) )
But anyways , I was thinking when you mentioned stacking and aligning , I haven't tried that in GIMP but I used to use DeepSkyStacker a bit , you can get some pretty good results with that. However I'm not sure if it would work for images with a foreground , but it might. Maybe worth a look.
I have heard of it, but mostly in relation to star photos without a foreground. If I cant get the results I want in Gimp I may have to revisit that option.