What Vairelome said. On #2 specifically, giving out other powers just because a player has Beast Change is like giving everyone who takes the Blood Drinker power Inhuman Strength for free because vampires are super strong. It's true of the creature type, but that just means that creatures of that type need to buy additional powers, not that they get them for free.
You could take Beast Change (Tiger), Beast Change (Raven) and Beast Change (Gibbon). Going by your ruling, the first would be by far the best one to pick, since it gets you Claws, Inhuman Strength, and probably Inhuman Speed for free (Tigers all have those things, after all), while the Raven gets only Wings and Diminutive Size, and the Gibbon gets nothing beyond the skill-swap. So, to avoid that problem, the mechanics are effect-based: All the power gives you is skill-swapping and passing for that creature. You want other stuff you need to pay for it (though you can, of course, use Human Form to get something of a discount).