I agree that one should not front-page their own nodes.
However, ...
My concern, is that until there is a way to stop people
from having more than one account (not likely to ever
happen), there really is no way that we could ever truly
stop somebody from front-paging something they wrote if they
really wanted it front-paged. All they would need to do
is log into their second account, author a node, and then
front-page it from the first. If we remove the ability
for somebody to front-page something they authored, we
would most likely only be encouraging this sort of thing.
Regarding voting on a considered node. I guess I really
don't see why you would want to stop the author from voting
on it. When a politician votes for themselves, we don't
call that un-fair, we call it democratic. Likewise, I propose that
the author of a node should have the right to cast a vote in
opposition to whatever reason it is being considered if they
wish.
I think the same logic extends to considering nodes.
What harm comes from preventing somebody from considering
their own node? The only time I've ever seen this
done is when somebody asks to delete a dupe. Why do we
want to stop that?