Just wondering: when did LDC become in charge of
determining
what Wikipedia's syntax should be?
WRT to the double/single bracket issue: We're suffering from a
legacy problem, since the double-bracket syntax was originally
uncommon (as opposed to CamelCase), it was okay that it was more
tedious than single-bracket.
The best thing from a usability standpoint to do would be to
switch from double brackets to single brackets.
An advantage of using double breackets only is that we'll then
be able to use single brackets as regular punctuation, which would
be especially handy in math articles, among others.
The answer to your first question is easy--you know where the code
is. Like everything else here in Wiki land, the "authority" falls
on the ones willing to do the work.