We have a single production database server right now with a single database
on it.  The TempDB is on it's own drive and the the Transaction Logs are on
a separate drive.  We currently perform nightly backups but I'm conserned
about loosing the transaction logs drive and not being able to recover it.

What I want to do is setup replication using  the current server as a
publisher and another server as a subscriber.  I can use dedicated NIC's and
Network with a gigabit connection.  I want to use this as a backup to
accommodate for an unrecoverable drive failure so that we only use minutes
(or hours) of data instead of up to a day.  The subscriber would be read
only unless the publisher server suffered from an unrecoverable error.

My questions are:
1. Does this make sense or is there a better way to accomplish what I want?
2. Should I be using transactional Replication?  (for the most up to date
data mirrored from the publishing server without making an entire copy of
the DB each time)
3. Will my primary keys be replicated without changing the values?
4. What is a reasonable expectation for sync times?  i.e. every 15 min,
every hour, etc...