You actually can stop the time by snapping you fingers, but it stops time for the entire universe, including yourself, with the exception of one single observer on some unimportant planet in the Andromeda galaxy. After 100 years from the POV of that observer, time resumes again.
We could have a whole vent diagram of people than stop time, start time, or be immune to it. Imagine just going out for drinks with friends when times stops. But this has happened before so you walk across town, go in some dudes living room, and force his fingers to snap.
“Ah! Oh it’s you. Time stopped again?” “Yup” “Alright. Well hopefully whoever’s stopping time this time doesn’t REALLY like to snap.” “Hopefully. Well might be seeing more of me again. Bye!”
No. You would have to snap ~25000 times, for the light originating from there, to even reach you (Assuming, that light is unaffected by the time stop).
If we take this in consideration and assume, that his equivalent of air is also affected and therefore cannot be moved. The affected would be stuck and unable to move and die of asphyxiation in a dark void.
EDIT:
Another interesting factor to consider is, that if the affected were able to move, he would have an undefined acceleration due to delta v / 0.
I saw a short story about a hero who could stop time but he could only see things he was looking at before he stopped time or was walking towards so only looking directly ahead. It was established by a thought experiment or something that addresses the reader. I really wish I could remember the name of the story but it was so long ago I don’t think I could remember the name even if I heard it
This hypothetical scenario assumes that stopping time is universal and instantaneous. Simultaneity in two reference frames, even when that doesn't make sense. Someone on earth snaps their fingers, and in that same instant, some unwitting observer spends 100 earth solar cycles in frozen, abject terror.
Various events around the universe occur on human timescales. If time stopped for use, we would effectively skip ahead on the view of them.
I actually think we could reliably catch 1 second time stops. Scientists monitor various pulsars. They spin multiple times a second, throwing off radio wave pulses. If all of them suddenly went out of sync with our clocks, it would definitely be noticed. It might take several, however, to prove it wasn't a weird hardware glitch.