Not sure how you would run class E into the circuit with aircraft required to be monitoring CTAF as well. This is already one of the confusions with how class E is at present, many VFRs are simply on the wrong frequency and not monitoring class E, they just treat it like class G. Class E would work to coordinate IFR, except at reduced rates, but won't solve the issue in Ballina, and that is random VFRs popping up in front of IFRs and larger aircraft that have less options to turn and avoid.
Perhaps - and I'm just 'putting it out there' - some VFRs don't 'do' E that well because E is the Class of airspace that exists on bits of charts in Australia but is - well, how do I say this - not the right colour/gender/race/religion. Class E is 'here', but let's not pretend it's welcome to the 'white guys'.
That little chunk near Avalon: Who'd have thought that the equivalent of a fart let off by a seagull sitting on a rock on a deserted beach could cause such sound and light, signifying ... whatever you want it to signify.
If a VFR was to then ram into your rear end or tail then there's more wrong than just continuing an approach, guaranteed there'd be a good chance if said VFR had an engine failure on downwind (or while discontinuing the approach), he'd be landing on whatever runway remaining between you and the end given no other options.
Yeah - all those engine failures that aircraft have in the circuit are a real problem - unless you consider the evidence.