I have had a check and found the pronunciation of all the kanji's listed have an 音読み reading
Yes, because I only listed on'yomi stem examples.
except 生 in 誕生 which I'm not sure if じょう is 音読み or 訓読み.
You can find しょう as an on'yomi, right? じょう is rendaku of it.
en.wikipedia.org
What I'm trying to say is that one can't really be sure of using ご for Chinese-originated words and お for those not.
You can think on-on combination is the most common for the stem of -suru verbs. Exceptions are very few, e.g., 仕事する, 試合する, 仕置きする, 仕訳する. These し are originally from the -masu stem of する, and 仕 or 試 are just ateji, so they are actually not Chinese origin, and have nothing to do with on'yomi.
en.wikipedia.org
There are many on-kun or kun-on reading combination
nouns, though. Incidentally, the former is called 重箱読み(じゅうばこよみ), and the latter is 湯桶読み(ゆとうよみ).
There seems to be many exceptions.
Exceptions are not so many. You can think almost all on'yomi stems are used with ご.
Incidentally, although 食事 is the stem of -suru verbs, お食事ください means "please give me a meal", not "please eat". Similarly, お電話ください is used only for "please call me", and can't mean "please call someone else", unlike お電話してください. 食事 and 電話 are not interpreted as a verbal noun in these cases, and ください works as a verb "give me ~", not "give a favor of doing for me". You can think お電話ください is a kind of set expression.
Not a strong order, but a gentle/tender suggestion, for instance.
Are there a lot of soft imperative verbs?
Special ones are not so many. What I can think of now is おいで (including ~ておいで), but "お + -masu stem of verb" has a similar nuance (e.g. お食べ, お行き, お入り). (おいで is also from "お + the -masu stem of a classical verb 出づ".)