I wish there was a "Are you sure?" dialog when invoking
"Close All", especially since the default shortcut for
"mark current word" (C-e w) and "Close All" (C-e C-w)
are very similar and it happened already more than once
that I accidently closed all open buffers.. :/
IMHO it might be a good idea to have a "Confirmations"
tab in the General Options where you could set this
(though the default should be to confirm it) and things
like "Confirm Replace-All" what came up recently.
Happy new year!