No. It inflates the size of the transaction when you process a send, possibly increasing your tx fee.
Yes, but it's still possible to spend these in a no-extra-fee or even 0-fee transaction (the
dust limitations are on outputs, not inputs). I did this myself recently (0-fee) with one dust and some of my other money, just because. I suppose it hurts the network some tiny amount, but it helps me some larger, but still tiny amount.
Shouldn't the miners be disallowing these 1 satoshi transactions? Why are they even being allowed in the first place? I thought "dust" was rejected?
As long as you pay a sufficient transaction fee to create the transaction outputs (usually 0.0001 per 1000 bytes), typical miners will accept it. Miners don't mind creating or spending dust, as long as you pay for it (they get paid, why not?). The ones I saw creating dust would have something like a 0.0004007 input, 70 1 satoshi outputs, and a 0.0004 fee (and come in just under 4000 bytes), thus meeting all requirements.
