Every day
Yes, a young dog can learn from an older dog. the young dog does not have to be young. just younger than the older dog.
If the older dog allows it - yes.
maybe. Depends on the dog.
your 14 moth old rottweiler may see your older dog as dominant so it may avoid the older dog to show it is submissive.
Yes, like humans, a dog's voice/bark will get deeper when they get older
A puppy can get jealous of an older dog but dont worry there can be a way like make the puppy be happy with somthing and distract them by somthing that will make them happy and not the older dog jealous.
It is possible for an older dog to hurt a puppy, especially if the older dog is not properly socialized or has aggressive tendencies. It is important to monitor their interactions and intervene if necessary to ensure the safety of the puppy.
no silly willy bob
Yes
With an older dog a trip to the vet is in order to make sure nothing is wrong internally.
Try to introduce him to the crate. If it is a house dog that is used to being free they may not like it. If not there shouldn't be a problem. It may upset the older dog.
It is probably trying to dominate. Because the puppy is younger, the older dog wants to show it that they, (the older one) are the boss.