My thoughts, aware some are repeated:
1 - Bring Back big fat rear tyres.
2 - More Aero, yes more Aero, but also reduce DRS to 1 zone and also look to remove DRS at tracks like Monza & Spa .
3 - Less run off tarmas areas - I know they are safer with the Massa accident in Germany. But can we not go with a foam like surface like they have on playgrounds then gravel, so there is no room for error, they can;t use the run off as pseudo track & cars wouldn't 'dig' during an accident....okay I'm not too sure if they would bounce
and how it would fare in a fire, but it is first thought, maybe not very well well thought out.
4 - Controversial - How about relegation to GP2 and a GP2 team promoted to F1 with funds to run for x number of seasons.
5 - Better F1 scheduling around other World Sporting events.
6 - Reduced ticket prices, a given.
7 - Tidy up the aesthetics of tracks, for example Hockenheim is a cracking track, but looks like it's been coloured in by a 4 year old! Call me a traditionalist but a circuit should be Grey/Black Tarmac, Kerb of a variety of 2/3 colours, run off area of gravel with the same colour of gravel all around the track, then grass or barrier where relevant.
8 - Balast vs points gained.