You can find these two source under these two heading 1) HOW IS BHUTAN FOR A COUPLE TO VISIT, AND IS IT SAFE THERE " in QUORA 2) PERMIT PROCEDURE FOR INDIAN TOURIST IN BHUTAN - a blog from THE HUMMINGTRAILS
You can find these two source under these two heading 1) HOW IS BHUTAN FOR A COUPLE TO VISIT, AND IS IT SAFE THERE " in QUORA 2) PERMIT PROCEDURE FOR INDIAN TOURIST IN BHUTAN - a blog from THE HUMMINGTRAILS
Bhutan generally doesn't welcome solo travelers, but if you can convince them right it can also be possible.
regarding couple, there's no such a policy in Bhutan. enjoy your trip worry less.
There is a question asked on Trip Advisor in the Bhutan forum. Unfortunately I'm unable to post the link. You can go and search over there. Apart from asking in Tripoto, you can also ask on Trip Advisor where replies from locals in Bhutan and international travellers are expected. Maybe that will help you out.