The 'big issue' with the system here is that 'supercandidate'
NotA behaves strangely. We can live with that for this election,
but I strongly advise against keeping it for the future.

"For/against/neutral" systems are used in real life is some
cases,[1] but always when there is just one subject to be
decided upon. This is not the case: NotA has an interference
effect so weird that when the voter expresses lack of trust
in one candidate, that negative vote is being transferrec to
all other subjects to be voted. I guess that the original attempt
was to express something like
1. X | NotX
2. Y | NotY
3. Z | NotZ
but the result of the tally will be:
1. X | NotX+NotY+NotZ
2. Y | NotX+NotY+NotZ
3. Z | NotX+NotY+NotZ
If we take it with a little humour, we could congratulate ourselves
for having designed a non-monotonic election system![2]

Regards,

Enrique

[1] E.g., many decisions in the Wikipedia comunity are taken
by this procedure.

[2] A system where increasing (resp. decreasing) the number of
votes for a candidate *does*not* increase the chances for that
candidate to become a winner.