Yeah, you got them right. Habang = "during" or "while" depending on the context.
Panahon = time; period of time.
"Habang panahon" = Forever, eternally, perpetually...
This is how it works:
"Habang panahon" literally means "while there's (the existence of) time ---> not time as a period or moment but time as a dimension.
"Habang panahon" is synonymous with "Habang buhay" literally "during lifetime".
Hope this helps. ;)