I have a hard drive developing bad sectors, and I want to boot into a Linux LiveCD to screw around and see if I can do something about it with badblocks.

The problem is, the kernel from the gparted LiveCD keeps trying to make the hard drive do something (why? just... why?) and keeps on waiting on the drive, which won't get better. It just doesn't boot, and sits there spitting out DRDY_ERROR or ATA timeout messages. Is there a kernel parameter I can edit GRUB with to make it not wait on the hard drive so long?

Well to answer your question yes and no. Any OS you are going to boot off of is going to probe for all the hardware on the system and setup the appropriate kernel modules to interface with it. You could easily disable the hard drive via the BIOS and your livecd would boot but then you wouldnt be able to access the drive.

At this point you may only be able to recover data via an advanced method and would be easier sending it off and paying someone else to do so since they have the proper equipment. It sounds like the drive is just b0rked. You could try attaching it via a USB and sometimes that has better results due to the way USB communicates with the system as opposed to a directly connected ATA drive.

Try almost any other live cd. The issue will come back when you try to run gparted. It will try to do some basic tasks. A bad disk may never be able to be mounted.

Run the OEM or generic diagnostic disk.

Exactly. But forget about the idea that trying to get this failing disk to work will be anything but a waste of time. If the diagnostic tools reports the disk as bad remove it and get a new one.