BUd, I dont think Peter's confusion would be over what tenchi nage actually is or how it is performed. but instead over its classification. I could easily consider tenchinage as a form of iriminage because of its entering body movement. in the same way that many (or all) throws can be considered forms of kokyo nage.
the technique you describe in post 18, our association calls that ude garami also.
Ude kimi ose has been missed aswell... difficult to describe. its like a standing gokyo pin with pressure on the elbow. good for knife defence.
I think when it is pinned on the ground some people call it Rokkyo.
aiki otoshi is in our sylabus also (I think it is atemi waza in shotokan).
get low behind your partner taking their balance and sweeping their legs away with your arms. dropping them in front or behind you.