3 questions about the Sony DSC-H5

I was taught to put a UV filter in front of the lens of all but the
cheapest cameras, but the camera I see sold now don't have that.
Isn't it still a good idea, to protect the lens?

The manual for the Sony DSC-H5 says it has an NTSC output for
television.. This is analog. Since digiatl electronics use ATSC
instead of NTSC, is this feature of the camera obsolete now when using
a digital tv or digital video recorder? That would seem strange since
I know the camera is digital and the recorder or tv is digital.
Maybe the manual means that "EVEN if you have only NTSC it
will work, and it goes without saying that it will work with ATSC
which is digital."

The manual keeps referring to a Memory Stick Duo card. Does this just
mean an SD card? It looks like an SD card and it's marked 2G. But
it says I cannot use a Memory Stick (What's that?), just a Memory
Stick Duo!

Thanks for any help you can give.