The feeling of inevitability is just you predicting something will happen; it's not evidence of something in the game itself but of a feeling within you. Unsurprisingly.
PA is bollocks, yes.
Unsure about your last comment. KO goals are a curse, but hardly evidence of scripting, just people being win-at-all-costs bums and bad defensive AI unable to deal with it.
Yes, there's the player emotions system that (among other things) influences the in-game stats of players, such as when they miss chances or do a bad foul – affecting their stats +1 or -1. But the "unwavering" stat I'm pretty sure just comes from the renaming of the form numeric system, previously 1-8. In this case, unwavering would be the equivalent of 8. (Or near equivalent: I don't know how many categories there are in the renamed system.) This only concerns the likelihood of a particular arrow for a whole match (not within a match) given the condition rating (A, B, C, D, etc.) they have.