Excellent advice, both in the post and in the comments. I only wanted to add that at least some readers (that I guess belong somewhere in between the skimmer and full reader categories) read the figure captions (and look at the figures, obviously) besides reading introduction and/or conclusions, as a way to see directly, but rapidly, the main results of the paper and how they are demonstrated. This obviously depends on the field, and I can only know for sure that it happens in my own field(s), stochastic processes/modelling of biological processes/other related fields.
I personally also do it for biology papers, because I do not trust the conclusions, but I’m not sure biologists do this.
It’s unfriendly in the sense that its values are not aligned with ours. I thought that’s what the U in UFAI meant. Luckily, it’s either not so powerful or not so misaligned that it will kill us all. But I think it’s more or less reasonable to say it’s unfriendly.