silent payment will not be transparent as it is not even existing on blockchain at all and the public will know about the transaction.
As far as I understand, this is incorrect.
The payment will not be traceable.
Let's say TPB accept Silent payments. Someone sends them a donation, which confirms on-chain. Nobody else can know TPB is the receiver, because they can't know which on-chain address belongs to their Silent payment.
If this can be like a layer 2, it will be better, in a way there will be a bridge between silent payment and on-chain transaction just like lightning network.
I don't think this helps: when opening a LN channel, there's no need to publish your address publicly.