as far as refueling goes, it's true that Formula 1 has a bit of a sordid history with it, but the fact of the matter is that it's a solved problem for other series. IndyCar has a developed and mature system for it, for example. I don't think that adding it back would be inherently dangerous if appropriately regulated -- and in light of Grosjean's crash, there's a counterargument to be made that having less fuel in the cars at any given time could offset the added risk of fueling in the pits.

Another thing that could help would be to focus on reducing the size of the cars. Over the last 10-15 years F1 cars have become enormous -- partially to account for crash structures and fuel cells, yes, but also for performance reasons. Wider track and longer wheelbase aid with grip and stability, but added size means added structure, and besides the cars are now too big to comfortably run at classic tracks like Monaco. Shrinking them down again would reduce individual performance, but improve the racing overall.