In the divisi chords, I would use full-measure in-accords, adding implied rests. Put the numbers before the notes with word sign indicators.
I would place the labels "tonic chord" "subdominant chord" etc as word expressions before the chords, as well.
In an example like #1, you could put a transcriber's note indicating there is no time signature. I don't know if it's necessary in an exercise like this to add a signature - especially with that first measure of nine stemless noteheads with fermatas on each one. There really is no rhythmic impetus in that bar. You could add a signature of 3/1 (with the dot 5 before it to indicate it's added by you) before the second measure but I don't know if it's entirely necessary. But that is certainly a possibility.
Hope that helps!