I like the pictures a lot. Nice captures and pp. Your problem is you mentioned 'HDR' and as soon as you do that it's all downhill from there with 'unrealistic' comments.
For sure hdr can 'kill' a photo. But it can also make one.
On Monday I was up in Rocky Mountain National Park. Come afternoon and the reliable thunder storms roll in. Try as I might I can not get those darn thunder clouds to look 'realistic' WITHOUT resorting to hdr.