emotion can we progress at all
A proletarian who is happy with his condition is just that much more alienated.
peace and rational discourse
No, and those two things aren't necessarily related. Rational discourse doesn't make history, classes do. Although it is part of the process of the movement of history through class struggle, it isn't nearly as large an independent factor as liberals think it is, and where it is a factor it is only in how it impacts the material base.
any "logic" that ignores the existence of consciousness and how it is impacted is denying literally an element of reality, and the most important one at that, not very logical, and inherently useless in its entirety (and doing the logic of something useless is itself not very logical)
a logic that covers consciousness, but is at all indifferent to it, is also inherently entirely useless and thus it is illogical to be used.
It is circular on a certain level (We are conscious, consciousness should have as much pleasure as possible and as little suffering, the word "useful" can only mean something having a quality which directly or indirectly helps maximize pleasure/minimize pain. So something which does not attempt to do so is inherently not useful and is illogical to entertain as an idea).
Regarding if Marxism in particular is wrong, it may very well be, but if it is wrong there's nothing I can do with that knowledge, it has no competition. Kind of how like if everything I knew about reality outside my consciousness and the qualia I am experiencing was wrong (I suppose it "could" be true [even though I can explain why we think about our consciousness and surroundings in that idealist fashion, that doesn't make it necessarily untrue]), but there is nothing I can do with an understanding that external reality doesn't operate the way I thought it did, for I would have literally no idea which actin to take, as every link between intention and action is informed by what I know to be wrong; I just have to pretend it isn't and continue to interact with it like it operated before. Same goes with Marxist science. For all its flaws, there is no other contender in terms of the science of historical movement. The basics of Marxism are simply common sense, it simply the only possible attempt to formalize a coherent system out of the relevant ones (there are environmental constraints on action, one of these constraints is social organization, social organization is people's action, there is no "thought" outside of those from our bodies which only have as information our actual lived experiences, the center of these experiences is what we do, when analyzing something we need to justify our abstractions, in order for them to be justified they must lead necessarily towards a more concrete thing, nothing acts in isolation from other things, no action takes place outside of an actual sequence of events, so no action can be analyzed outside of the actual sequence of events, etc.).
If I abandon Marxism, all I have to go off in terms of informing my social action is what I know to be parts which necessarily connect together to form something which is wrong. So I have to abandon literally all understanding of what the consequences of my actions are in the context of human society. I must revert to ethical platitudes, but with not even an understanding of how to mold my action based on them.