I wouldn't worry too much about the few bad sectors at the moment. However, I notice that the temperatures have been above 50C, and that each drive has hit the High Fly Writes threshold. I don't know significant the latter is in terms of data integrity.
However, I wonder if drive #2 has some problems:
0A Spinup Retry Count 97 100 100 217
BC Command Timeout 0 100 3 78906686
C7 Ultra ATA CRC Error Rate 0 200 1 109755
The actual number of Command Timeouts is not 78906686, but 1342. The attribute is best viewed in hexadecimal.
78906686 in decimal = 0x04B4053E in hex
0x053E in hex = 1342 in decimal
The Ultra ATA CRC Error Rate would suggest a communications problem. You may like to switch cables and/or SATA ports to see if the problem stays with the drive.
I don't know if it applies in your case, but see this thread where a vertically mounted drive developed bad sectors in the vertical position, but not horizontal:
http://forums.seagate.com/t5/Internal-A ... /m-p/42506Notice that three new drives behaved in exactly the same way, so it may be a design issue rather than a genuine fault.