urine trouble!
The dog is marking it's territory. It's normal for a dog to do that.
If your dog is still peeing on the couch, then you have not trained him/her well enough yet.
A dog can stay without peeing for max of 4 and a half hours
You need to take the dog to the vet ASAP.
Peeing.
get him used to peeing with the leash on, so he'll get used to it.
By peeing
shoot it
he's marking his territory
yes
Simple: don't yell at your puppy. The fact that your puppy is peeing means you are overdoing it. Correct your dog firmly, but without yelling. Peeing is a sign of submission, and you are scaring your puppy.
Positive reinforcement or punishment... You can show it where to pee and give it a treat when it does. or If it pees on the other dog, look at the peeing dog and yell "no" it until it stops. Either should work but positive reinforcement way usually works best.