One thing that needs to be remembered is that Class E is Controlled Airspace and therefore VFR flights in contact are provided with a control service.
Class E airspace is controlled airspace, right. But in class E airspace only IFRs are controlled and not VFRs ! How could a controller control a VFR traffic that can transit without calling !
I'm sorry but VFR traffic is controlled in E airspace only in airfield circuit !
That means that when a VFR calls you in E airspace you shouldn't give him any control instruction (except again in the circuit), you can watch him, provide info and alert and that's it. If he request assistance, you can provide guidance but normally under any circumstances no orders should be issued. That is the way I see it, but maybe I'm wrong.