I've mostly refrained from writing ASOIF fanfic because of GRRM's request (only two little ones, really). But if he dies before he finishes the series, all bets are off.

I thought it was a bit excessive for both the Kzin and the Puppeteer females to be sub-sentient. But the female Kzinti are sub-sentient because the males paid to have them gene-engineered that way. Presumably the Puppeteers have not paid to have their females gene-engineered into sentience because:
1) They can't afford…

Frack no. I posted a one-shot to fanfiction.net and got years of people clamoring for more. I explained that it was a one-shot - WYSIWYG. And they kept asking for more.

Base it on GRRM's short story "And Seven Times Never Kill Man" if you want dark.

ASOIF is an entirely different case than his stand-alone novels, being a series.