I'm somewhere in the middle on this. To my mind the fact that Danny signed Lee and Amir tells us something about how he views KO and Sully...probably as guys whose development isn't critical. Or at best, as guys who aren't ready to be solid starters.
The fact that we haven't signed vets in the backcourt seems like more of a good sign. If Danny had signed a vet PG who'd take minutes away from Smart, I'd be bummed out.
I agree, the moves indicate a lack of faith in Sully / KO / Zeller becoming starting caliber players. A lack of faith I tend to share, to be honest, but I'd still rather start Sully / KO in the hopes of showcasing them or a trade (or on the off chance they surprise us) and then give the backup minutes to Mickey and / or some young guy we pick up.
As for the backcourt / wing, my main issue is that Bradley and Turner are still aboard. Neither guy is "old" per se, but I view both as finished products, and I don't view either as a particularly good player.
To a lesser extent, re-signing Jerebko (a player I like, in vaccuum), falls into this category. Jerebko is nice and all, but signing him to the same sort of deal as Amir suggests he's also a stop-gap / placeholder for a trade to be named later, and whatever minutes he gets could go to Young / Hunter / Crowder / Mickey / Olynyk instead.
I guess I would have preferred to see Danny make more moves like what Portland has done, acquiring young, athletic players who might show something when given a larger opportunity, and leaving open holes in the rotation to see if any of the younger guys can step up and prove themselves to be reliable contributors.