Yes, heres a step by step tutorial explaining how to do it http://www.wikihow.com/Add-an-External-Hard-Drive-
yes it will work fine just remember to format in fat32 so the ps3 can read it. also partition it into about 4 to improve read/write times.
Er no you dont, if you partition the HDD you run the risk of the Partition table not allowing it to show on the PS3. At best youll only get the First FAT32 partition.
Thats fine if you want to hide another File system from the PS3 but bad If you want to use the hole 2TB space.
Example 320GB USB drive. 3 partitions
SB1 - 150 GB EX4 Linux boot and windows repair ( this won't show on PS3 wrong file system)
SB2 - Fat 32 76GB
SB3 - Fat 32 75GB
Both SB2&3 are fat32 file systems only SB2 will show on PS3. SB3 will never show up...
Not 100% sure if they still are but Western digital My book 2TB drives. DID come Fat 32 formatted.
This is because they were sold as universal USB drives... MAC OSX, LINUX and Windows ready and the only format that works like that is Fat32. (The OS have problems Writing to each others file systems other wise)
Thats a place to start looking any way untill others post and you can start looking at prices.