The collisions in E in the USA are often trotted out by Australian ATCers to scare people about E.
There are 15 or so aircraft collisions per year in the USA on average, however the great majority are in the circuit pattern or near the airport, a big chunk happen in CTA, so their system is far from perfect. Funny enough same in Australia, multiple collisions in GAAPs, so they changed them to class D with the same circuit patterns and join procedures, so basically no changes to what caused the collisions. The near collision at AY with the ATR and PA28 was only averted by TCAS, which says a lot about the usefulness of CTA for modern aviation. The AY incident spells out the dangers of CTA where you assume the tower is taking care of separation, where in a CTAF I assume the ATR crew would have been grilling the PA28 for position and intentions and sighting them. BTW I'm not saying the CTAF situation is any safer, just that you can make killer assumptions when you think someone is looking after you and have dropped their bundle, the simple analogy is the train crossing signals not working, it's then more likely a collision will occur because drivers are not expecting it to fail and are not looking for trains.
They cannot operate VFR but they can operate in and out of airspace and aerodromes without any ATC, mixing it with VFR non-transponder aircraft in VFR conditions, which conditions result in the pilots of the RPT aircraft having to operate 'see and avoid' (hopefully alerted but not guaranteed alerted).
Yep it's the rules, nothing can be done without rewriting those lines in various operations manuals.