Well, Runepriest isn't MY cup of tea, but my guess is it can be made to work, maybe with a little MCing and feat work.
As for the Binder, its an icky class, IMHO really the closest thing to a fail in 4e. I mean, you can play it, and if you have fun with it then that's awesome! OTOH its supposed to be a controller, but its got nothing in the way of real control. It simply fails at it's primary role and isn't even a decent striker. Amusingly a regular PHB1 warlock can simply access all of the powers that come with the Binder (they are just warlock powers, nothing stops you from selecting them) which means basically anything good the Binder got is not really specific to it anyway. This is of course true of many subclasses, but most of them at least have a reasonably compelling set of class features, which this particular class utterly lacks. Nothing in 4e is unplayable by any means, but if he's going to feel the sting of being somewhat underpowered in combat then he might try something like the straight warlock (which is a pretty good controller, particularly the feylock). IMHO you can easily achieve equally good flavor, but of course that's just me...