Linux filesystems

I’m an Ubuntu user and I just purchased a WD My Passport 1 TB external drive. While copying large files I noticed that the speed was lower (30MB/sec) than expected. I read somewhere that this will increase if I format the drive to ext3/ext4. However I have the following questions-

1- WD is not officially compatible with Linux filesystems, so if I format it to ext3/ext4 will it null my warranty?

2- Has anyone tried this and experienced ANY problems over a period of time? No hard drive corruption, damaged sectors or anything?

3- Since I’m using ubuntu, I did not notice any installation software or anything. After formatting anything that came with the drive will be lost, so will I still be able to revert back to NTFS and use it the way I’m using it now?

Formatting the drive does not void the Warranty.

We do not support this drive in Ubuntu, meaning we do not provide additional assistance in the event of problems since is not one of the operating systems the drive was manufactured to work with.

The drive can be formatted back to NTFS or any other file system of your choice.