1- No refuelling during the race. Each team is provided a set amount of fuel for the entire weekend. Would drastically improve fuel efficiency technology relevant to consumers.
2- some other non-brittle form of material for suspension components.
3- agree with steel brakes or some other way of lengthening braking distances. Want high tech material?--try titanium alloy.
4- front wings lower to ground and less wide (up to the inside of the front wheels maximum).
5- rear wings only one element allowed (would have to be worded very carefully to avoid loopholes) and back to 2008 width.
6- why no ABS? F1 being so safety crazy it wouldn't hurt. And its road relevant.