The cloud statement pointed more toward Super-Id Ne (weak, valued; Tertiary or Inferior) than it did to an Ego S function, even though the presence of Super-Id Ne theoretically confirms the existence of Ego Si.
Statements 2, 3, 5, 7 are fine for this purpose; I included the 'S blocked with rational function' format to specify whether or not the S element illustrated was + or - in sign.
4, 6, 8, 9, and 10 were indicative of other elements that might or might not be able to specify what the person's S preference is.
6 could possibly indicate Se Auxillary, but only under the circumstance that Fi is Dominant. The example is more likely to point toward +Fi. Unless of course example 6 is a expression of gratitude that is common courtesy, in which case the example would line up more with Fe valuers.