B. You might be able to read the contents back if the lock bits were not set to prevent reading them back.
If you could, you would get a series of hex numbers back that would not be usable.
You might be able to Dis-assemble that and then have assembly code listing.
A. Perhaps. You would likely need a High Voltage (just 12V) to unlock the chip so you could re-program it.
If you check http://www.avr-developers.com/
(if I spelled that right)
there are probably core files to support the chip.