Seamus,
wow, scary pictures, but to the point:
A bunch of other files were found to be corrupted and I am not sure what should be done about them.
Probably just some archived (packed) files that can't be unpacked - not a big issue, most of the time.
There is an "Extract" option. Is the "Extract" option a tool for extracting and eliminating the virus?
Nope. 'Extract' just lets you export the file from the chest (like Restore, but to a different folder). If avast! can't "heal" these files (which it appearently can't in your case) - it just quarantines them to the chest. They are safe there. You don't have to worry about them - unless you need them.
BTW: Hantana is a dangerous virus spreading by means of Kazaa (you do use Kazaa, right?). The Trojan-Gen might be a false positive - to be sure, you can send the file to support@asw.cz (i.e. extract it from the chest and attach it to the mail).
Hope this helps,
Vlk