The problem is that Amiga OS 3.x can only work with drives upto 4GB (2^32), the instructions were for a 813MB drive.
Otherwise it will think your 30GB HD is actually something else.
You need a more up to date file system, such as WB 3.9's FFS or something like SFS so it can recognise bigger hard disks!
Also, uaehf.device is for Hard Files not hard disks! Please remove or change it to scsi.device or whatever instead.