Now that Eye for Weakness is fixed I think Blue Flame Blade is just the most powerful thing to be doing as a spellblade, and it's not even really close anymore unless you have some roleplay or other non-gameplay reason not to soulbind and/or bring Viv. The fox den is your convenient one stop shop for almost everything, as well. Rindo and Nakano have your Chrysanthemum Petal and Blue Flame Blade, Kohaku has your Kunai and Lucky Strike ring(s). Agility derived stats are increasingly replacable the higher you level, so I personally always go agility/cunning/willpower to start and then switch agility for strength at level 7+/ in Act 2, because
-damage from accuracy is marginal at high crit rates, and your crit rate is going to be very high
-evasion from agility is literally worthless when Juiced
-the initiative difference between full agility investment and none is made up by a single equipment slot (the reverse is not the case for strength)
For your non Blue Flame Blade abilities you pretty much have a few categories of thing you want covered
-a chunky single target weapon attack that applies a DoT (Venom Strike and the new Closing Storm are both great)
-a weapon attack that hits all enemies plus some upside (Whirlwind, Fury Strike, Deadly Shadow)
-a buff of some kind (Venom Strike can pull double duty here, Flames Within, Night Shroud)
The normal play pattern is buff if you act before Viv's turn 1 grease, your first action after the grease is your "hit everything" ability, and if there is anything left alive after that (rare, but happens) you hit it with your remaining single target button.