I haven't tried feeding mine any pinkies so I'm not sure. However, I do remember learning somewhere that you don't want to feed your dragon something that is too large for it too digest. So I guess it would depend on how big your lizard is. General rule: Don't feed your lizard prey that is larger than the space between the eyes.

Yes the frill does grow bigger as your lizard gets bigger :0)

Hand feeding tip: Have you observed your any feeding time patterns for your lizard? By that I mean is there a time of the day that it likes to eat? This might be the best time to try hand-feeding. Likely it will take time for your lizard to adjust to the idea of taking food from you, if it doesnt take it readily.

best of luck