full_page_writes = off?

Hi, would full_page_writes=off increase the risk of inconsistency or db
corruption in 8.3 and FreeBSD 7?

fsync = on;
Definitely "on", as single power outage after three years is guaranteed
to make your life interesting otherwise.

synchronous_commit = off;
Can be "off" in my case as I'm not doing any "external" actions based on
transaction's success or failure (if I understand the docs correctly).
So I don't care at which moment the evil strikes as long as the db is
consistent.

full_page_writes = off;
AFAIK when this is "on" it means synchronous WAL writing with less
impact, as it occurs once per checkpoint, but it's still synchronous.
Not sure at all about this one. How would FreeBSD 7's UFS survive the
power crash etc. with this set to "off"? OTOH, does "on" play well with
synchronous_commit=off? Meaning, will the transaction holder get success
immediately on commit, still guaranteeing consistency?

Thanks for any insights or clarifying missed points.