Here is some mor ammunition to try:
If no success, you can get original installation disks by calling Apple. Have the serial number ready and a credit card. There is a fee. By using the installation disk, you should be able to get to you HDD and repair it unless it is totally dead.
The other option is another trip to the Apple store genius bar and have them deal with it.
The answer to question #1 is possibly, but I cannot say with certainty.
What the Installation disk will provide is access to the internal HDD in Disk Utility. If the HDD is corrupted, then you should be able to make it functional again. If the HDD is physically malfunctioning, then a new internal HDD will have to be installed.
If you are in the USA, the phone number is 1 800 275 2273. Have the serial number of the MBP ready and a credit card.