Using Croc for Sanguine:
If you want highest survivability, use Ternion +1. Reason being, you will Sanguine at higher frequency, meaning more self-cures, or more availability when you need it, & Subtle Blow.
If you want highest enspell damage because you know you're going to be amnesia'd a lot, or you're fighting something goofy like Tenzen with his two WS avoiding abilities, use Ternion +1.
If you're fighting something like worms or rabbits in woh gates (or any Adoulin targets just under Apex for difficulty), use Ternion +1. Reason being, a singular Sanguine is going to one shot anything you fight in this range of difficulty, so it's more efficient to have the Subtle Blow and higher Frequency of attacks (enspell and TP generation).
Otherwise, if you're trying to maximize overall damage output, and the target is harder than the above, use Tauret.
For Sanguine Blade, is INT (for dINT) or MND (for WS mod) better?
from what I have read, INT is better UNLESS one is using Crocea Mors C, in which case MND is better.
INT is better if you're using a weapon other than Croc. MND is better if you're using Croc. Reason: It seems to function like dSTAT does not get the Croc's Elemental WS bonus. So the INT component is not boosted by Croc, giving way for MND to lead the way. STR remains weaker than INT or MND regardless of main hand weapon, but it catches up to INT a lot with Croc.