on the two questions:

1. Is it proper for a society or military to regulate or prohibit adult, consentual sexual behavior?
Yes. E.g., a prohibition vs male-female fornication on the sidewalks of Hancock's 200 block. Gee, maybe even a prohibition vs male-male and female-female "fornication" on the same sidewalks.

2. What is the basis of individual's rights and law?
In the US: "We the People of the United States ... do ordain and establish this Constitution for the United States of America." Always start with the People and Their Constitution.

Where you go from there, to establish a constitutional basis for gay rights, is not one of my priorities. I'd suggest that, so far as as "original understanding constitutional theory" is concerned, gay rights are definitely out there amongst the constitutional "umbras" and "penumbras".

Regards

Mike