I have no idea exactly what or where the corruption is and from your description neither did the Genius.
Your existing hard drive will work OK for that wipe and install but do not restore from TM.
I suggest all new installation of all applications and fonts not included on the install discs, leave the old ones where they are.
I am not sure how to recover those addresses without recovering corruption unless you do the OS install, grab the addresses, email them to yourself or save them to another external drive, I also suggest printing them so you have a hard copy, if possible.
Do much the same with other non replaceable items. I expect that you will find problems along the way but they should be easier to handle.
Those 50,000 emails I would save for last and make sure all else is saved where it can't be corrupted.
That is my best advice from past experience with similar issues.
I do not know how it will work on TM if at all but that is all the life preservers I have.