That should capture the noise folding, although of course the ideal nature of the controlled sources will mean that they are not capturing any device noise of the equivalent blocks in the design - but apart from that, it's fine.
You cannot use an ac analysis, because this is not a time-invariant linear system. You can't use pss, because if it is a fractional pll (a sigma delta), then there's no periodic solution; so it's a non-periodic time-varying system. Secondly, the z-domain controlled sources also suffer from "hidden states" and so cannot be used with pss.
So transient is your only solution here, I think (from the level of detail that you've provided, at least).