Can non-humans have more than 6 forces in an area?
Nope. Powerful beings (Demon Princes, Archangels, old-time ethereal gods and the like) can apparently do an end-run around this limit by having powerful Words, etc. The Game Master’s Guide discusses ways to quantify – or not – Superiors. The limit for PCs is 6 per area and 18 total. Period. (This is a change from the previous FAQ entry.