I'm not so sure I agree with the track argument. Yes, of course its true that eventually as speed increases the tracks will run out of run-offs. Tracks can be modified, re-design, built differently to suit new safety requirements. I would like to see faster straight line speeds, but not much faster cornering speeds, I guess (see: physical challenge).
Imo they need to be a looot harder. Max one change per race, maybe even none. Small flatspots would be less costly, drivers could push for longer. Bring back refuelling to keep pit stops and strategy, come up with some way of minimising danger of fire. Deadman's handles, bottles instead of massive, high-pressure rigs.
Tbh, tying in with the speed and aero sections, I suspect that we'll reach the limits of human endurance before track safety. Tracks and cars can be design to be safer, humans cannot. At some point with tyres made of superglue, ground effect, over-body aero and ridiculous speeds, the Gs will become too much to handle. Also, I have no problem with F1 not requiring the most fit people on earth. Aero could be increased if harder tyres were to be used, as a way of balancing things out.
DRS should be free to use at any time by any driver, if there isn't a specific reason that makes its use excessively dangerous. I.e., disabled during safety car periods, in yellow zones and in the rain. Otherwise it's game on. The time difference based rule is a disgustingly artificial way of hiding more fundamental issues with F1 aero. Bring back ground effect but dictate rules in such a way that they can't cause complete bottoming out and loss of control. Consider Indycar style aero elements around (read:in front of) tyres, makes a significant difference. Look into possibility of reducing turbulent air caused by the rear aero elements so that cars can find it easier to follow closer. Similarly, if there are ways to direct the airflow downwards to reduce water spray in the rain, that would be something to work on.
Improvements are a bonus, not a big one for me although wider rear wings and slightly narrower front wings I'd not mind at all.