I’m aware of this site, and I figured that was what you were using the moment I saw your screenshots. It’s generally very good, and I wish I could download their pitch accent engine into my head, but I have found one isolated example for which it doesn’t quite match reality: 寄生虫 and 帰省中 were pronounced identically in the NHK videos that I was able to find, but the OJAD says they’re pronounced differently. Perhaps some usage has changed over time, or there are multiple acceptable pronunciations.
My mistake. I figured that you might be able to vaguely guess what pitch variations were indicated by the markings in the summary table, but perhaps they weren’t very clear, since reading pitch variation markings does require a little experience with the subject.「 indicated the first high syllable, and its mirror image (which I can’t type) indicated the last high syllable (i.e. the accented syllable).
I think the problem is in fact the fact that you’ve been using a verb, whereas most of the particles in Japanese get attached to nouns and can’t always be attached to verbs. Another thing: the OJAD is punctuation-sensitive, so adding question marks and so on could change the results.
か – this is the question/uncertainty particle, so there’s no way it would follow the rules. Tone changes depending on the nuance to be conveyed: an actual question would require a rising tone, whereas an almost-flat, slightly falling tone would imply a sort of mild acceptance or even resignation
が – this isn’t the usual particle usage, and would be interpreted as the conjunction that usually translates as ‘but’ and occasionally as ‘and’. I can’t be 100% sure, but all the sound bytes I have in my memory require the pitch to fall. It only stays the same if the speaker is hesitating/waiting for approval.
し – same problem: this is practically a conjunction, and unless someone is very excited/emotional when speaking, the pitch always falls on し.
ぜ・ぞ – these are both masculine sentence-ending tone particles. I don’t think any tone particle follows the rules: they all change the pitch based on the emotion expressed, and the default way they’re read in a plain statement requires a pitch drop.
で・に – で seems to preserve 平板 for 乗る, but neither of these particles usually attaches itself to a verb.
I’d suggest you try testing the particles with nouns like すみれ or the pronoun これ, both of which have a 平板 pitch accent. That aside, unfortunately, the pitch accents we expect aren’t always preserved in actual sentences, so that may limit the usefulness of studying dictionary pitch accents, even if they’re still good to know.