A lot of opinions seem to be of the sort that BK had a plan that he is now executing. That it all means something. Him staying silent, him saying this or that, him taking his phone along to a murder etc.
IMO, a lot of that is bias. We heard right of the bat that he is "a phd student in criminology" and now we think that he must be smart and there must be a grand plan. Had it been told that he's a loner who used to work as a fish cutter, the impressions would be different. As a fellow phd student (and on my last year, not first year) - a lot of phd students are not smart, and even if they are, this does not have to mean that they are smart about everything that they do.
I think he is just a sad guy who did a cruel and evil thing based on emotions. And fk-ed up. And did not really think as far as getting caught. And that his online masters degree has nothing to do with it other than indicate that he has had at least interest in (if not fantasies about) crimes for a while.
A lot of my own ideas about BK probably are indeed biased based on his education. But in my perspective, it has never really been about how intelligent he is, but how intelligent he
thinks he is. Almost like he had something to prove, maybe.
Did he plan it out? I believe he did with the crime itself (not the court stuff), to some extent, but I don't think of it as a reflection of his intelligence as much as a reflection of his personality and motivation. That's just my best guess, though.
Realistically, as you said, BK's education may have had absolutely no bearing on anything to do with the crimes. We don't have to believe his old professors and others about his being "brilliant," because who really knows. Even if, his common sense could be nil. It's just for me, personally, with his background in cloud-based forensics, I'm not ready to dismiss his education yet. This was what he wanted to do with the Pullman PD even, so it was seemingly a strong interest of his, imo. To imagine he was so stupid that he was oblivious of the things he learned and was interested in doesn't seem likely to me, either. I agree, he f'ed up. And I wouldn't be surprised if the only thing he's remorseful for is his mistakes. But f'ing up also doesn't equate to lack of intelligence or planning, imo.
I wonder if we'll ever find out what was going through his head in the days, weeks, and months going into the murders.