GypsyComet
SOC-14 1K
The only problem I have with Supp 4 is that it brings in skills that would need to be in the 6 Book 1 careers. Wet-navy Sailors can earn Gravitics and Battledress; Space Navy and Marines can't.
Admittedly, it's easy to rewrite the Book 1 skill tables.
Although it's just as valid to rewrite the Supp 4 tables. That might even be a better idea if you don't think Gravitics, Battledress or Zero-G Combat are all that necessary.
Re-write six careers to add a few things, including a more vigorous use of skill cascades, or rewrite twelve to remove those same things. Note that skills are already being worked over by the inclusion of Book 4 even if those careers aren't in use.