Yes it is called littering
It depends on the laws where you live.
yes
Only in California. Then they get to tax the owner for it.
It shouldn't be, as long as it says to clean up after your dog instead of 'no dogs allowed'.
If it is your own dog there is likely no reason you should not pick up the dog. If it is a strangers dog it is not a good idea. Some dogs do not like to be picked up and will bite if you try to pick them up. This is more likely to happen if it is a dog that doesn't know you.
yes, if your dog has fleas
you can try training him to pick it up
it means you should not pick him up
Yes. A dog eating any type of feces can cause the dog to "pick up" a parasite(s)
Step on the white stuff near the dog
your dog probably is hurt.
the dog is sad very sad!