[wst_]

All the examples you gave are pretty obvious to read because of suffixes, called okurigana, or the other kanji next to it. Problem arises only when the kanji stands alone and that doesn't happen so often as people think. Even when it does, most often than not, you can infer the reading from the context.

[gray_-_wolf]

わたし (私） and わたくし (私） is probably my favorite example. Good bless furigana. きょう (今日） and こんにち (今日） is sometimes fun as well.

[glandium]

だいにんき(大人気) and おとなげ(大人気) can be fun too. The latter usually is followed by ない, which wouldn't usually happen with the former, but the usual way I'm hit with these is in sentences where the word is at the end of the line (or better, when the line ends at 大人).

[visarga]

In some cases you need to read the whole phrase to know what a word meant and how to read it.