For the drives it would depend on the drive connectors. There's nothing to stop you using the hard drives, Older EIDE motherboards typically had 2 EIDE connectors on them allowing you to connect 4 EIDE devices, 2 0n each channel. Newer SATA motherboards typically only have 1 EIDE connector allowing you to connect 2 Eide devices.
It would depend on what type of motherboard you have, and if the drives are EIDE or SATA, if they're SATA then you're limited by the number of SATA sockets on your mobo 1 for each drive. If they're EIDE then you're limited again by the EIDE sockets on your board, 2 drives per socket in this case.
You also have the option to buy a drive enclosure and convert an internal to an external USB drive, these are usually quite cheep.
As for the mobo question, it's entirely up to you, do you want to spend money on a board that you say has bent pins and risk it not working? I myself wouldn't bother.