Now, to be fair, I've only used the Whelp (and the Presence) in Limited formats
Lo and Li, Royal Advisors were clearly made to support Persistent Petitioners decks, though its odd that the payoff for milling your opponents is to pump your team
So, in most decks this card advantage and the loss of your third turn when your opponent is generally going to be playing something strong (such as Goblin Rabblemaster, Brimaz, King of Oreskos, Anafenza, the Foremost, or ramping into Siege Rhino) is going to be too much of an investment for such a small benefit
Some make amazing cosplays, others create beautiful works of art, and others buy a rare piece of its history for a whole lot of money
Yes, see the Combos section above for the infinite combos this archetype can assemble
(For example, I've been playing a Mono-Red deck without any Goblin Chainwhirlers