Passcard 3 and M3 can't damage your DS.
Only flashing it so you no longer NEED a passcard can hurt it.
Web and email and aim and MSN are coming soon.
DS games through M3 are AWESOME. Just look at the M3 Wiki for compatibility lists.
You can run Linux...but I dunno how it is.
I answered 3, then 2, then 1.
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