+1. I think Mt Hood and Liberty are at least moderately interchangeable with German Hallertau, whereas Motueka and Saaz maybe not so much for a traditional BoPils. I do like Motueka in an American-type ale blend though.
It depends on how it used. Sure, the citrus notes are going to come through in a big way if one late hops the heck out of a beer with Motueka (most modern craft beers are over-hopped). However, Moteuka is used as a substitute for Saaz on a regular basis because it has Saaz's spicy notes in addition to the non-Saaz notes. The same can be said about Liberty. Liberty is almost like a caricature of Hallertauer. As an aroma hop, Liberty leaves Hallertauer in the dust.
With that said, would I use Moteuka instead of Czech Saaz? Well, if I am going to use an imported hop in a Bohemian-style Pilsener, it would have to be the real thing. However, seeing that I prefer to use whole cones with a false bottom, I tend to use the U.S. triploids Sterling and Santiam in my Bohemian-style lagers because high-quality whole cone Czech Saaz is difficult to obtain via the home brew trade. Neither hop is perfect for the job.
With respect to yeast, well, there is huge difference between Saaz (Bohemian) and Frohberg (German) lager strains. Members of the Frohberg family of lager yeast strains have an additional set of Saccharomyces cerevisiae chromosomes, which makes them less cold tolerant and more attenuative. Saaz strains produce a beer with more residual sweetness. Saaz strains also tend to be more flocculent than Frohberg strains, which means that they tend to leave behind above taste threshold diacetyl. I like a touch of diacetyl in my Bohemian Pilseners.