You seem to be pinning all your hopes on ground effect. I don't believe this will make any perceivable difference to the viewer (the drivers will probably notice it)...but only time will tell.
With regards to aero - yes they have taken away a lot of the appendages. They have reduced the wing sizes, yet the dependence on aero is MASSIVE. Eddie Jordan kept telling us that there were going to be MASSIVE reductions in aero, during the Winter of 2009/2010; however, this never happened. There was no explanation given for this, but I think its fairly obvious.
In 2010, however, they did reduce the size of the wings. Did it make any perceivable difference to the viewer? Nope. Alonso and Petrov will testify to this.
The problem is that aero research is progressing at such a fast rate, that as quick as the FIA tighten the rules on aero, the teams come up with new methods to regain the lost aero.
Teams will certainly agree to small reductions in aero (which is what has been happening over the last few years), as they are confident that they can regain all the lost aero in a single Winter. To make a massive reduction in aero would seriously compromise all the hard work which the richer teams have put in over the last few years.
The teams who would agree to aero reduction are the back markers, as this will allow them to close the gap on the big teams. Unfortunately for them, the bigger teams are those that have the bigger voting power.
...Oh and in case you are thinking that the FIA can force teams to adhere to the new rules: they tried to force massive budget cuts and the top teams threatened to break away from F1 and start up their own series. The FIA in response had to back down and reach a compromise which the big teams were happy to go along with.
With regards to engines: my understanding is that the FIA never asked the engine makers to go backwards. What they did was freeze development. Thats all. Unfortunately, the same cannot be done to aero development, as aerodynamic computer simulations are all part and parcel of designing a car. It is nigh on impossible to freeze aero development.