Isn't the entire premise just dumb?

Not really. If you can control human emotions you can control your citizens. Logic rules the day.
And it's not really a novel concept...it has been done many times before.
There's another thread on this subject with other variations on this theme. I would also throw in This Perfect Day by Ira levin along with things like The Matrix, 1984, THX 1138," "The Island," "Equilibrium," "The Giver," ...

Actually it may sound goofy but having seen the movie, it is a fascinating look at a society conditioned to supress emotions like males in our society are told to hide their feelings. To "suck it up"

Good movie

There are many novels and films which use this same premise of a dystopian future where emotions are suppressed through technological or psychological means.

You make a good point about the redundancy of saying "thank you" but I would not say this is a plot hole by any means. We say "Hello" and "Thank You" hundreds of times a day as a purely automatic response. When I say "thank you" to someone for holding the door or handing me something, it doesn't really hold any emotional value to me, it's just an automatic response. Obviously these are polite phrases which evolved to serve the function of maintaining a civilized society in which people feel like they are respected and cared for by others. But now they are mostly just automatic responses to somebody interacting with you in a facilitatory manner.

So I could invisage a future where emotions don't exist but people continue to use phrases like "Thank you" to acknowledge somebody doing something to facilitate you, such as prescribing to social norms by holding the door for your fellow citizen. It would almost be a vestigial trait, like the human appendix - a remnant of something which once held importance and purpose.

I so understand what you mean. It's impossible for humans to survive without emotions. It goes against logic. There's millions of examples that can comprove this, but I'm sticking with the most obvious one. How the *beep* were they supossed to have babies and grow metally healthy individuals? Even if they did inseminations or in vitro fecundation and then insemination it still makes no sense simply because that baby needs someone to provide him/her love and care. Of course they can give them the appropriate "care" and education but that alone would make them emotionless, insenstive "people"...
For this the concept the movie was produced on makes no sense whatsoever. Nevertheless I kind of liked the movie cause of the two main actors, the caracters they played and the love story they shared.

An emotionless, or at least emotionally suppressed utopia, is the only kind that can exist as a society. It was a concept touched on quite a lot in The Matrix actually. The machines tried to engineer a utopia where all mankind would be happy together but eventually realized that the wildly different personalities and desires of different people meant that such a place was fundamentally impossible to provide. With that possibility out of the way, you have to either let people live in society as we understand it today, where people are mostly free to pursue what they want but certain rules still apply to everyone, or you can go about trying to alter human nature itself, either through indoctrination, medication, messing around with our genetic structure, or a combination of the above. Heavy indoctrination is already used in authoritarian collectivist societies around the world and if those in charge of such a society figured out how to engineer a medical treatment or gene therapy that could get rid of a person's baser impulses while still preserving their ability to function as productive members of society, they would certainly do so. This movie explores that particular "what if" scenario.

The name of the movie is EQUALS okay.

People are always talking about how all man should be equals, this movie is an idea of what an 'equal society' would be like.

Not only financial equality would come to play but also people couldn't be more popular than others, no ego etc so there has to be a void in people's personalities for a society to be truly equal which this movie plays on.

And also there was talks of a great war in the movie at one point, I believe that that was they suggested that world leaders came together with the idea that the only way to keep peace (and eliminate crime) is if people don't have any emotions and are truly equal to one another in every way possible.

And injected the newborn babies with something that would render them emotionless, ocassionally that would fade out for some and the natural emotions would still come out (SOS).

And the reason that peoples emotions were such a threat to the government or whatever is because they were happy in their emotionless but peaceful world and people with emotions are a threat to that.

As far as the 'thank you' politeness that was just trained behavior, usually stuff like that doesn't mean anything even in the real world but is just courtesy.

So it makes plenty of sense.

We don't have a dog. That was just some really violent sex.

How often do you perform perfunctory social rituals that if taken at face value would involve meaning or emotion but in reality almost never do? They're reflexive rather than indicative of feeling, and because it doesn't much matter one way or another, those working to shape the interactions between people within the Collective would have no reason to attempt to remove it from the list of acceptable behaviors.