As for automatically accepting top vote answers, see this question:
My answer was:
There are many questions that do not
have satisfying answers for the OP,
even though answers are upvoted by the
community. Accepting is totally up to
the OP, as it is a means to reward the
answerer. Doing this automatically
would actually be missleading as it
would look as if the OP awarded the
points, thinks that his problem is
solved, and therefore late answers
after some time would be discouraged.
The OPs accept rate would be flawed as
well. Would the OP be able to unaccept
the answer, and accept an other one?
Or leave it with no accepted answer to
start the game again?
This holds as well for the moderator accepting.