I'm afraid that I find the idea of repressing our most basic instincts (which is a good part of what makes us so bellicose) rather untenable, for several reasons. Our brains evolved this way over a very long period of time, and most of the more ancient mechanisms have a survival potential necessary to the brain's basic functioning and development. To interfere with that is to stunt proper development at various stages, leading to serious imbalances. More, perhaps, than any other field of medicine, this is the one that deals with the most delicate aspects of biochemistry and genetics, and also with those the most finely calibrated and most easily distorted or damaged. This being the case, I rather doubt we'd see such advances for a very, very long time; and in the meantime the road toward such advances is likely to be so packed with botches that there's going to have to be an overriding concern obvious to the majority of people with any voice, politically speaking, for the necessary research and experimentation to be continued; otherwise, the backlash (as it will inevitably have a high human cost) is likely to be abrupt and permanent. No, I'm afraid we human beings are a damned long way from being capable of even virtual godhood.
There is also the other side of the coin: such artificial alterations in our most basic mental/emotional life would, quite literally, mean we would no longer be recognizably human, but something other. I'm afraid that there aren't that many who would be willing to take that chance on losing the things we hold most dear, the things that do make us uniquely us, in order to achieve a possible outcome of the type you describe -- I doubt the majority, when really faced with such a choice (rather than a speculation on such) would even do so if it were a certainty, let alone anything less. And would you really want to suppress the emotions? Remember, no emotion exists in vacuo; they are all so intertwined as to compose such a complex knot as would make the Gordian example appear as a 5-year-old child's puzzle in comparison. Such things as love/hate/affection/aesthetic appreciation/anger/joy/hope/dreams/etc. are all so closely related, and so inextricably intertwined, that even the tiniest alteration in one is quite likely to affect or diminish them all; and the outcome of that is much more likely to have disastrous effects than otherwise (the chances of the outcome being beneficial being in the statistical minority). It is likely to increase the incidence of neuroses and psychoses, of sociopaths, etc., because the brain (and its product, the mind) is not only the most delicate aspect of the human organism, but also the most individual organically and electrobiochemically (as is shown by the incidence of harmful effects of various psychotropic pharmaceuticals on various portions of the populace -- look at the varied effects of the same antidepressants on even genetically-close relatives, for example); we would be dealing with statistical averages, rather than individual minds, or else we would have an ever-proliferating number of techniques and treatments tailor-made for each individual, which would simply become too costly to support, and too fraught with dangers should the tailoring be off by even the tiniest scintilla. And that's not even addressing the effect of such altering the emotional makeup on family life and children, or even child-rearing (if it were only done for the adults, so that the children's brains could mature and develop naturally; as delicate as the adult brain is, the developing brain of a child is a billionfold more complex, because any alteration of circumstances exterior or interior can so alter the neural pathways being created at any point).
This is something we may one day achieve, but it is likely to be very, very far in the future because of the nature of the thing. More than anything else, the interdependence of brain function and mental/emotional life, personality, etc., approach the uncertainty limit (not that they work in quite the same way, or should be seen as similar in physical properties, but rather that the uniqueness of each brain is similar in difficulty in regard to certainty of effect of any action on its functioning where the complex known as personality is concerned), and this raises the risk factors astronomically. It is one thing to medicate those who have obvious mental/emotional problems that make it difficult for them to function daily; it is quite another thing to take a "normally" healthy brain and alter its functioning for such an uncertain and nebulous posited future result.
Also... what are we, as individuals, if not our memories, hopes, dreams, aspirations, emotions? Pure intellect is a very cold thing; pleasurable only because it is tied in with our thalamus and reinforced by those brain chemicals which give us a sense of well-being and pleasure when it is being exercised in its purest (achievable) form. Suppression of memories is, again, an extremely delicate thing. Certainly, we nearly all have some memories we'd prefer to eliminate ... but eliminating that particular portion of a neural web without affecting those we wouldn't wish to disturb or alter is quite another. The "primeval drives" are also what drive us to achieve when circumstances around us seem overwhelming; those drives that push us toward aggression are what keep us afloat in such situations. Let's face it, the complexities of the brain-functions that produce the mind are such that we are more likely to understand the deepest complexities of the exterior universe itself long before we sort all that lot; certainly before we would be anywhere near having enough information to achieve the delicacy of touch necessary for what your post proposes.
