Of the changes over the past 11 years that haven't been canned already (I know he said 10 but 2003 was a bit of a watershed): Personally I'd keep:
Slick tyres (although that change was merely correcting an error from even further back)
New-for-2014 engine formula
Knockout qualifying format (feel less strongly about this one but I do see its merits compared to the old free-for-all)
And get rid of:
Post-qualifying parc ferme rules
Rules on components life and associated grid penalties
Starting on the tyre you qualified on
Mandatory two compound rule
Any form of getting backmarkers out of the way on safety car restarts (either waving them through to unlap or putting them to the back)
Permanent driver numbers
Let me think about this...
Post-qualifying parc ferme rules - wouldn't this remove an element of excitement where a team compromised their quali set-up for good race-pace, and hence had a chance of coming through the field? Without parc ferme, you'll get the fastest cars at the front, the slowest at the back, and the quali order will be mixed up much less. Hence worse racing.
Rules on components life and associated grid penalties - doesn't this just make the spend on engines and gearboxes much more?
Engine freeze - doesn't this reintroduce the possibility of an all-out engine war which will cause teams / engine manufacturers to once again spend hundreds of millions on engine development, thus driving said teams and manufacturers out of the sport?
Spec tyre - doesn't this just make the sport much more expensive?
Starting on the tyre you qualified on - doesn't this reduce the excitement in the race as everyone will start on new tyres and on the optimum tyre for whatever strategy they pick, thus reducing the excitement in the races?
Mandatory two compound rule - wouldn't this mean that all the cars would run on the optimum compound all race, thus vastly reducing overtaking as there would be no speed differential?
Any form of getting backmarkers out of the way on safety car restarts (either waving them through to unlap or putting them to the back) - I like this idea?
DRS - debateable
Permanent driver numbers - what difference does this make to anything, apart from maybe making it harder to tell which driver you are looking at?
Double points - agree
I'll be honest, doing all of the above, you'll end up with a massively more expensive formula, which will allow bigger differential between the front to the back, and you will remove most of the features which allow excitement. The fastest cars qualify at the front and drive away into the distance. I think some people forget how excruciatingly boring some of the races were back a few years ago, with nary an overtake to be season for races at a time.