A1: If you are using internal waveforms and not introducing any user waveforms, none of the 1GB is consumed
A2: Yes. [UTILITY] "Contents" -> "Data Utility" menu, click on the Waveforms folder and look in the upper-left.
https://www.yamahasynth.com/ask-a-question/where-is-used-sample-memory-information/latest
A3: No. Motion sequences and source/destination mappings are just regular parameters.
A4: No. All MODXs (assuming latest firmware level) have the same factory waveforms so there's no "need" to pull them out. There are no provisions for this. You have to sample your own instrument if you want to do something like this - say to edit a "waveform" (or approximation of this).
A5: FM-X doesn't use any waveform memory. Only custom non-factory waveforms do and FM-X, by definition, do not ever have these. Also AWM2 does not use any user waveform memory unless the Performance has custom waveforms (user and/or library). And, in case you're wondering, user and library slots consume waveform memory in the same way. The distinction in user vs library is how Performances can be saved/stored. Libraries only allow for saving/erasing all Performances at once into a Library slot - while the User bank allows for Performances to be saved/erased one-by-one. Custom content in each consumes waveform memory in the same manner no matter which area the custom waveforms reside in.

FM-X also has a few structural differences that make it a better candidate for certain behaviors of sound. The envelopes are slightly difference in a way that matters at times. The way portamento works is different - so FM-X is sometimes the best way to achieve certain "glide" effects, etc.

If your only concern is waveform memory consumption - then AWM2 referencing all internal waveforms is just as small of a memory footprint as FM-X.

On the other resource consumption hand, polyphony may be a good rationale for using FM-X when you can.

Jason,

Very precise and helpful answers.

Thanks.

The reason I asked....

I have my eye on some 3rd Party expansion packs. KSounds Organimation and Easy Sounds Phat Analogue I&II.

Now I know that any performaces I create won't chew up memory, I'll go ahead and purchase.

Thanks again.

Those 3 libraries consume 468MB total.

I've got the Kapro CS80 already in there (some convincing sounds for Pink Floyd Animals Album).

Leaves me about 60Mb wiggle room.

Cheers.

The secret to Flash Wave ROM is to not install data you don’t use. While the libraries may consume lots of memory, if there are Waveforms installed that you never use, you are just wasting that memory.

From any purchased library, you should use Library Import, to import just the Performances you are likely to use. By doing this you can create your own version of the .X8L File to install. You can then Delete the purchased Library and install just your streamlined version.

Thanks BM..