It was like Campbell and Ted Raimi were winking at the audience the whole time saying "look at how comical we can be." It felt really forced and I don't even know how anyone can categorize it as a horror movie. And Campbell pussed out and didn't show any T & A at all. WEAK.
I honestly feel like you are over-thinking this movie. It didn't seem forced to me, it just felt like a silly film made for the sole purpose of fun - fun for those involved and fun for the viewers. And I think it accomplished that goal.
And as far as T & A... I hate when directors cast themselves in a movie and then include graphic sex scenes starring... themselves. Frankly it comes off as more than a little creepy, and although I have no problem with Bruce engaging in sex scenes when he's not the director (like in Running Time, which will make you see Bruce in a whole new way), I'm glad he didn't go that route with MNIB.
I don't feel I'm over-thinking it at all. The film is made for die-hard Bruce-Campbell fans (which I am not-I don't hate the guy. I think he's a competent actor, but I just don't worship the smell of his farts like some crazed fans of his do). I found it a bit boring and you didn't really dig that ending, did you? As for the T & A, I don't mean that I wanted to see Campbell in any sex scene (that would be gross), I'm just saying that since the movie is obviously and purposely done in a "campy/cheesy" way, they should have shown some flesh (especially when they had some attractive women in it as extras and also the very attractive lead actress). As well as maybe amped up the gore, had a better "villain/monster" than the one they had and it would have added to it and made it a lot better. Since Campbell had no problem with dropping F-bombs, why stop at that?