The thing baking my noodle is: can you use EvoThaum to automatically hit someone for whom you have taken a sympathetic link (via a Maneuver)?
I vote "Yes", but only technically so. Because one of the capabilities of Thaumaturgy (which gets inherited by EvoThaum) is to wrap up an effective attack roll into the complexity of the spell. I've already talked about how the ultimate expression of this -- the complexity 26 or so conflict-in-a-single-spell -- is technically possible but impractical due to the control roll. But you could presumeably due lesser versions of this (ie, the 'inflict a serious consequence' sorts of thaum spells).
So what would this look like? Say I'm the Summer Knight and I'm using the happy-fun-sparkly Summer Magic to ... oh, say shove a bit of the summer sun up a Red Court Vampire's ... uh ... gut. Looking at doing this with Thaum, I would note that 8 shifts (beyond the attack roll) would be enough to either inflict a serious or a mild+moderate against the vampire (Hey, look! Sunlight satisfies The Catch! Whee!), and I decide that's good enough for now. I also need to account for the RCVs defence, which seems as though it would be based on Endurance. He can roll up to a 6, so I'd need complexity of 14, which means EvoThaum would need 14 shifts of power to do this, and it would count as an attack hitting with an attack roll of 6 and weapon rating of 8 (sun). Tough for most character-level wizards without taking a few consequences themselves. A lesser version of this could guarantee a mild consequence for 10 shifts of power. Of course, if the RCV did poorly on his roll, he might well take a greater consequence, but darn it, these things sometimes happen...
Most of the time, just casting it as an Evocation would be more effective. After all, if you had the skills to pull off a control roll of 10, then casting a 10-shift attack evocation would inflict at least 14 stress
even on the best possible deffense roll. That's enough for a mild+moderate+severe on that RCV (assuming he is enough of an NPC to even take that many consequences!) Of course, the EvoThaum option gives you the flexibility of not needing proximity or line of sight, which is a nice bonus (assuming you have the required link, of course).
At least, that's my take on the situation.