Server :: Smartd Configuration Options - Monitoring And Logging

I'm having some trouble understanding the smartd configuration options which go in /etc/smartd.conf. I've had smartd running for close to a year now, and read the manual page for smartd and smartd.conf several times, and I still can't get my head around it properly. This is what I use in smartd.conf:
/dev/sda -H -f -S on -o on -n standby,q
-s (O/../.././(00|06|12|18)|S/../.././11|L/../../(3|6)/21)
-m <nomailer> -M exec /usr/sbin/smartd_mailer
The above works fine (I use a custom script because I use exim). However, I had two failing hard-disks on two different machines (sector pending attribute) - but I would only receive warning emails if I restarted the machines - not when the periodic tests were being performed. I have a number of questions, if any of you would like to share some light on this:

1. It is not clear from the manual page how the monitoring and alerting mode works. Do I get an initial email when I start smartd if something is wrong, and then no other warning email after each scan, even if there is a fault, unless the fault goes worse?
2. Can I force it to send me warning emails after each test (offline, online, short, long etc.) if the fault condition is still there, even if it hasn't gotten worse?
3. There seem to be a variety of parameters monitored. I was thinking that if I monitor bad sectors, and the hdd temperature - it should be enough to warn me when the hard-disk is failing? Would the -a switch in smartd.conf cover these?
4. I don't understand the difference between monitoring and logging in relation to alerts? Do I get alerts only if I log things?
5. Do I understand correctly that the -p and -u switch would warn me of *any* changes in SMART attributes, even if they don't represent risk of failure?
6. Is there a way of finding out if the scheduled tests (offline, long, short etc.) have been performed?