Oh, one more thing: If you switch to Void, you don't get any invocation opportunities, since there aren't any for Void (the generic ones still apply). If you're not concerned about that, it can still be worthwhile, because there's also no Void backlash - so you can go ahead and keep all the strife symbols you want!

You're right. I just found the section that breaks down what constitutes a technique's activation and effects. In particular, a check is listed as only one aspect that makes up an activation. Also, the "Effects" section further makes the distinction. All of this can be found on pages 173-174. 
Also on 174 is the section on "New Opportunities" that should clear up question C. if ever there was any doubt. 
Thanks again!