Well, that is another consideration, it just wasn't clear to me from what people were saying that they were exclusively talking about pact blades (and ones that are daggers at that). It still relegates the whole thing to that woolly definition of 'wield' which is not exceptionally clear. WotC would definitely be clarifying the rules considerably in general if they would unequivocally define wield. As I say, I'd give him the +1, no doubt.
I'm still quite skeptical about the SA thing though. When you use a pact blade (dagger) as an implement you are not "hitting with" the implement, so by strict construction I don't think you would get SA damage with a ranged attack power delivered with it. More to the point I think it may be unbalancing. Eldritch Blast with SA damage attached is pretty nasty. I'd have to seriously consider how that would balance vs what a rogue could do with SA and a ranged weapon. Since only dagger, crossbow, and sling qualify for SA at range it really devolves down to what is the best crossbow you could use? Indeed AVs Superior Crossbow delivers d10 damage (and at better range than any spell), though it requires load minor and a feat slot for proficiency. So the comparison at that point makes it reasonably even. Power Swap feats are the final consideration, though I'd rank that as a much lesser objection since they are limited use powers and they would replace things that could give fairly similar advantages.
So, on the whole perhaps it isn't going to overbalance the character. There may still be some gotcha associated with PPs, I'm not sure and I'm not going to spend that much time delving into every possible PP that might be available to the character to find out, but I am leaning towards the idea that it would be OK.