Cisco Firewall :: PIX 525 Anti-Spoofing Attack Protection

I have multiple questions about the PIX 525 software version 8.0(2) ASDM 6.0 (2)I am a windows network admin that is new to Cisco and routing in general. I have read through the forums and the Cisco documentation, but have not been able to fully understand the topics discussed within.

1. Anti-Spoofing Attack Protection
2. Scanning Threat Detection - Auto Shun
3. NTP Sync Verification
4. QoS implementation5. IOS and ASDM Backup
 
This option is currently DISSABLED for all interfaces.I know what ip address spoofing is, but what is the functionality of these options specifically? How does it work and should I enable it and for which interfaces? Second Question: Scanning Threat Detection - Auto Shun
 
I found this option in ASDM under: Configuration --> Firewall --> Threat Detection.Enable Basic Threat Detection and Enable Scanning Threat Detection are both currently ENABLED, but Shun Hosts detected by scanning threat is currently DISABLED. Also, the Networks Excluded from Shun field is empty. I know what the shun command does. I have used it many times when I have been fortunate enough to catch some piece of **** trying to spam my mail server or gain access to it.
 
What I am asking specifically is how does the Auto Shun work? Should I enable it and what are the potential consequences? Also, what exactly is a scanning attack?
 
I am not familiar enough with the PIX and with the topics discussed in the document to successfully apply the info within. Plus, I'm not sure it covers the kind of basic, all-inclusive bandwith cap I would like to put in place.
 
The goal is to cap the maximum internet (outside) bandwidth that inside5 can use to a reasonable percentage while allowing the other interfaces to have the remainder.

How would I go about this implementation? 2. Is there a way to allow inside1 - inside4 to use max bandwidth when there is no traffic on inside5?
 
I am probably, at least, the third owner of this device and I do not have an account with Cisco nor can my tiny (perhaps non-exsistant given the current economic state) IT budget afford any form of support or software licensing with them.My goal is to backup the IOS and ASDM data in the event that I have to replace the device due to a hardware failure.
 
I found a file transfer function within ASDM which allowed my to copy the files pix802.bin, asdm-602.bin and tfp from flash to my desktop computer. I also have a copy of the activation key info and my current configuration.
 
1. Have I backed up all the data/info I would need to restore this software and ASDM to another unit.
2. The activation key screen also has a serial number field. Is this the hardware serial number or is it for the software? and is it tied to this device specifically or can I use it to restore another unit if necessary?
3. Is there anything else I should do or be aware of regarding backup and restore for the PIX?
4. What is the tfp file?