Dick
Explain what you mean by VMC climb without clearance.
Do you mean 'VFR climb'? or 'IFR pick-up'? Or mixed flight rules flight 'VFR to IFR'?
You cant just say im IFR in VMC so am gonna climb regardless. That is reckless. Just because you can climb without a clearance in G doesnt mean you can do it just as safely in E. Why stop at E, why not just climb regardless in C or A with traffic info?
You would've received a traffic statement whilst taxiing which will cover the initial TI, but not necessarily on something transiting at 8000, because you are initially only going to climb to 4500 or below. What happens if when you get airborne ATC are dealing with an emergency or weather avoidance etc you cant get in to get a clearance and decide 'Im VMC' im just gonna blast into class E. you could end up flying into IFR traffic you dont know about.
Equally, You've pushed a lot of non-transponder traffic down a lot lower (below 4500) when previously they could be below 8500. so you've reduced the space for missing each other, reduced the flexibility of VFR and IFR flights and increased misunderstanding of the procedures, caused IFR flights (in a couple of directions of travel) to initially have to climb to a level that is nearly 2000' below the LSALT (outside of 25miles). The margin for error has been reduced not increased.
If you want clearance on the ground and increased safety, make it a class D control zone to the ground, then all traffic is known. Or even better make Tower ATC be present for all RPT arrivals.