I think the labeling of Micchi as a psychopath is a little misleading. Based on what I have seen, I would say he is more of a SOCIOPATH rather than a PSYCHOPATH.
1.) His background. Growing up in a controlled environment led him to possess a desire to have control for himself. Also, along with this privileged upbringing, he does have a sense of entitlement which leads him to do these things. If he were psychotic, he'd be doing these things out a biological compulsion.
2.) His skill with manipulation. Sociopaths, despite their lack of empathy for other people, are very charming and can easily blend in with other people. Psychopaths are usually violent and tend to be unable to interact well with others. The sociopath is more likely to manipulate other people into being violent instead and can actually deal very well with people as we have seen Micchi do, none of the group suspecting he has an ulterior motive.
3.) His care about Takatora, Mai, Kouta, and the rest of Team Gaim. Psychopaths don't really have care for anyone, but the sociopath may have one or two people they care about, even if it's more so as a pet. And we've seen that, at least to some extent, he cares about his brother and the team, albeit the way he sees it is twisted by his own desires.
I don't know if this real changes the way anyone here sees Micchi, but the main point I wanted to make with this is that everything Micchi is doing is based on an active choice (sociopath), rather than some uncontrollable compulsion (psychopath). It's planned out and everything. Do I find Micchi somewhat sympathetic? Yes. He's just a kid who has had the majority of his life dictated to him and simply wants control over his life. Do I think that gives him a pass for what he has done? Not a chance. Wanting to control one's own destiny is one thing. Thinking one has the right to not only control their own fate, but the fates of everyone around them is another.