Hi,

[no idea about RNG, sorry]

>I'm a little worried because I don't know how to figure out how big
>the code that my instructions are going to create is, and my project
>is going to use a *lot* of instructions; how do I make sure that the
>instructions don't run into the space I've got defined for my
>variables? will the assembler move around them, or do I have to take
>that into account?

Variables are stored in the data segment which is the usable bank of
RAM (256-bytes). The rest is stored in code segment, either ROM or
in the very most cases, a bank of Flash ROM.

>Lastly, does anyone have any clue how to get two VMUs to talk to each
>other over the link?

It's done throught Port 1 and its associated registers but I never
used it myself so I don't know more about it.