As far as I know, only Power vs. Chaos and Skaven on weapons is a forbidden combo. Maybe DR vs. both on Necklace too. Attack speed and Crit power certainly is available, I got it several times today (to my frustration). The rest is just bad luck.
In general, only mechanic-specific Properties and Traits are limited to particular weapons, any others are limited by item type. Power vs. both is specifically denied on weapons, as FS didn’t want to give us a “generic” Power bonus, usable against everything. It slipped through to Charms anyway, and was removed even from them for a little while. That was reverted primarily for consistency and fairness reasons, though (as it happened after the game had been out for a while already and people were using that particular combination, so it would’ve been unfair to new players).