I can't see anything an admin could do within the
policies of any
Wikimedia project that would put them at risk legally.
In addition to everything a Wikipedia editor could do which would
place him or her at risk legally, an administrator could also run a
risk by undeleting defamatory material previously hidden, failing to
act in a reasonable manner when notified of defamatory material,
making defamatory blocking summaries, blocking an editor who attempts
to remove defamatory material, protecting articles to prevent attempts
to remove defamatory material, placing defamatory material on
protected pages, and abusing his administrator privileges to copy
defamatory material and publish it elsewhere. And that isn't by any
means an exhaustive list.
I think only about 2 or 3 of the things you list are both illegal and
significantly related to admin abilities, and even those would not be
within established policy. An admin doing the kind of things you list
would be a rogue admin - why would the WMF protect rogue admins?