Hey Carl. Thanks for checking out the post and taking the time to write a comment on it. I'm glad that you liked the explanations.
Coming to the elevation part, yes apart from Mangan we were above cloud level - so pretty high up. As per Google,
Tsomgo Lake (#1, #2) is at about 12000 ft.
Mangan Waterfalls (#3) is at only 2000ft.
Zero Point (#4,#5) is at whooping 15300ft.
Thanks for reminding me, I will now add these new information to the original post for future readers.
RE: Some pictures from my trip to Sikkim, India last December