Isn’t this one just zenpan though?
This one is probably because of the repeater, I’ve seen those rendaku and sometimes not rendaku
City names?
Actually these consist of a pre existing kanji combination, followed by an extra kanji. In those cases, rendaku and sokuon never occurs, so that’s definitely a good exception. I found this in a different topic:
Those last ones are a pretty good point though, words made of other smaller words do not adhere to those rules.