1)
chances are you have a corrupted ISO CD image

When booting the LiveCD, use the "Check this CD for defects" option, and see if it's ok - but I recommend re-downloading it anyway

Also, try burning the CD at a lower speed
Cheap CD-R's do not play well when burned at high speeds - drop down to 4x
also, if the CD-R's have been improperly stored (like next to a radiator or something) this can severely affect them
optical media is extrememly fragile, especially recordable ones
If all else fails, get some different discs

2)
As for the wireless, that's easy
I'm 99% sure that your wireless card is natively supported (just from googling the model number you gave)
however, you will need to get the right drivers for it
The drivers are probably not built-in to Linux
it's a broadcom card, and they, like Nvidia, haven't opensourced their drivers, so they're not built-in to Linux - you will need their proprietary drivers

You will need to connect via wired ethernet
then goto System > Admin > Hardware Drivers
at which point you can download the restricted driver for your wireless, and install them