If I wanted to write a lengthy review of the product, where would I do that? Is there some official channel to send that like an email address?

You could try, but they probably won't reply, or even read it.

You could do it right here. They browse the forums occasionally. Other than that you could do it on something like metacritic, but then you'd just be a number. (I doubt they have the time to read every single user review)

I'd say do it here. Best chance of them perusing your thoughts on the product.

There are millions of players, each with their own opinions. Yours are probably worth something, but when you divide out by the number of players, the value drops dramatically. If they read your review, they would have to read all the others to find your gem. It would take them over a million times what you estimate they should give you your due. So say you give them something that should take 5 minutes to read and think about. Multiply that by a million. Divide it by 60. Divide that by 24. That's the number of days that you would have them spend reading reviews rather than working on games.

There's a presumption that every customer would write one. I suspect the number of people that would bother is a small percent. Then they can filter out any that have f-bombs with software and just count it as bad. But yes, it would still be considerable work. Any company that sells anything in high volume has this problem. Since Bethesda is not sending out surveys that can be machine processed (they should), I don't really have a good option here.

Dunno about that... there are quite a few on this forum that have written extensive dissertations of what they like/dislike about the game. You may as well post something too and get some discussion going around it.

I think your best bet would be to publish it wherever you can Send an email, sent a letter, write here...

If I knew an email address for this, I sure would.