First - sounds like a wild ride.
Did the industry pro explain the rationale for rejecting your title? My not-industry-professional gut tells me that Psychos and Psychostar suffer from the same problems:
(A) Those with mental health issues, and those closest to them, may find it offensive. Modern use of the term "psycho" is heavily stigmatized, thought demeaning by many, and there's no point in turning away potential readers with the title. I don't know if I'd go as far as re-writing your book to not use the term, but you may want to approach a couple "sensitivity readers" to determine whether it's a good idea, because again, there's no point in turning off readers by a simple word choice. Unless you're cool with that possibility, in which case hey, go for it;
(B) Because of that stigma, and because of Hitchcock bringing Robert Bloch's "slasher" novel to the mainstream zeitgeist, many potential readers may find that title misleading. They'd get it once they read far enough, but they might not do that or may not end up purchasing it because it's not what they expected - maybe they think it's horror-oriented, maybe a cerebral meditation on mental illness in the future, etc.;
( C) It's not particularly descriptive or captivating. Since your milieu is unique, but the word "psycho" isn't, you may want to look for something more special to your story.
Because of ( C), I feel "Arkfall" is the best of the three options you offered, as it's the only one unique to your world. That said, it's not a very "active" title, certainly not compared to your logline. "Solar Storm" may work, assuming it's directly referential to the story content, but it's very broad and not especially evocative. I can't suggest anything else, not knowing more details of the characters, plot, or setting.
I'm also a little confused by the logline itself. Revenge is personal. Why is she exacting revenge, and what is her relationship to the CEO? If her identity/relationship is a secret/plot point, you might want to consider losing the word "revenge," and rework the logline to explain that she's "on a mission" or such so you don't give anything away. If she's in fact just a hired gun and it's not personal for her, "revenge" doesn't seem appropriate unless you specify it's someone else's revenge she's exacting.
Let us know what you come up with!