i would call it
"Strange Senses [–1]. You may instead define a small set of up to three thematically related
supernatural senses."
yes.
Im unclear if you need to buy supernatural sense to take strange senses, and im inclined to say no, but i believe many of the one point powers aren't worth the cost.
The first two examples, smell and sight, are physical senses - using Alertness and Investigation? The third example, "feel", is a mystical sense - using Lore?
I view the power as essentially giving you new ways that you can use existing senses. as opposed to supernatural senses which gives you an entirely new sense. the description in the book both supports and damages this theory but that's my working interpretation. so as to which skill youd use with each sense? im not really sure it matters. do you use alertness or investigation to spot something? whicever makes the most sense at the time. same for these new uses of your senses.
In your campaign is the difference between virginal/pure people, impure people, and corrupt people a significant difference? Otherwise, in game terms, both of these would seem to achieve the same effect. It seems like you are paying one extra refresh to add some colour to the description. Also, you have chosen to spread your senses over three different skills rather than concentrated in one skill.
its more that, supernatural senses gives you one new sense ability or unnatural bonus, strange senses gives you three that are all tied into a specific theme, so in this case its that you can sense a person purity and some of the things that affect it. when a person lies they are intentionaly defiling themselves and as such you see some of there purity boil away in a smoke like fashion. you can smell people who are high in purity[ either they smell repellent cause innocence is icky, or they smell appetizing cause.. yum!} and you "feel" comfortable around those with little to no innocence like you would around a close friend or lover.
As to how important the distinction is, that really depend son who/what the pcs are, if your playing fallen angels, demons, and or angels it definitly couldbe, but no i dont think its worth 2 refresh, i think it should cost one.
so if i was the gm it would be
Strange Sense [-1], Strange Senses [-2], Broad Senses [-3])
Strange Sense [-1], one specific thing you couldnt normally do.
Strange Senses [-1], 3 things you could do if such a thing where possible tied to a theme/ sense one thing 3 different ways
Broad Senses [-2]) other wackiness.