I'm right there with you...
What is funny is that I had 2 sentences about a series with an energy (erg, BTU, calorie...) budget and a $ budget and not much else but wasn't sure that should be F1 and deleted it from my lat post.
I'd like to see the energy or both budgets drop each year by some percent.
Not sure about restricting aero at either end, or fenders. Tires in open air is so 1950s.
800KG is OK, but 900KG or 1 ton might be even better for a minimum.
I'd be tempted to make the rule that Aero is open, but you can't replace it if it fails or gets damaged. This also deters some of the the delicate exotic materials and things hanging off the ends of cars out in harms way.
Heck, I might even support "bumpers" from 6-10" off the ground. Not trying to turn them into stock cars, but I am a bit sick of all the shrapnel strewn all over the course on any contact.