Storing SQL Server System Databases On A Seperate Drive

I see not reason for moving them at all -- they are small DBs that are cached in memory pretty much all the time. You are not going to make changes very often in those DBs (writes) to have them moved to another drive to gain some additional performance.

It depends. There are some cases where you might want to put them on a dedicated drive (which I've done once or twice). Usually this is in a clustered setup where you can't put them on the OS drive, and you don't want them on the drive with the user databases on them, so a separate drive it is.

I couldn't think of any reason to move your system databases to dedicated drive.

It's good (and recommended) practice to dedicate drives to TempDB and all user databases - as a very general directive.