... this is what I would do:
- completely independant Federal Bank & Mint (think Bundesbank or ECB) ... this alone would solve a large chunk of all of todays problems in the US
- redesign, reprint and reissue of the dollar (forge-proof like the Euro or better)
- healthcare system, dutch refund-model (maybe some good parts of the German model, ... maybe, really not sure about that ... not sure if there are any good parts of the German model you could salvage in a meaningful way ...)
- "Loser pays all" for civil lawsuits, nationwide (this is a total no-brainer ... one of the reasons many people consider the US a tad wacko ... it boggles my mind how anyone can think of their nation as a land of the free where this rule isn't in place ... ), audited lawsuit cost support for the poor (German model with independant lawsuit feasibility evaluation along with it)
- NRA becomes official authority (Goat becomes gardener), mandatory 80 hour training, education and licencing required for any semi-automatic gun or more powerfull ones (nationwide)
- communities may create firearm ban zones where concealed non-single-action firearms are not permitted, these zone are then enforced by a nationwide law / ruleset
- ban of death penalty (nationwide)
- transform of anglo-saxon precedent law system to a more continental-european rules-based law system with revision opportunities (no more locking away of people for 25 years for stealing a slice of pizza or any of that sort of bullshit possible with todays state of affairs in the US ... land of the free bladiblah ... my ass)
- mandatory civil or military (personal choice) service of 15 months for all full-aged that have finished highschool (think the former German Zivildienst doing health-care support, community service or military service, all would be gouverned by a military type system, civil service would get same pay and follow the same disciplinary rules and order of rank)
- 5 years tution free college after completed civil-service + optional 3 vacation semesters or, as alternative, 4-5 years of regulated and guilded "Apprentice of Crafts" / "Master of Crafts" education, training and diploma (think German "Master of Crafts" model ("Handwerksmeister")) ... interest free gouvernment loans for the time of enrollment in college or "Master of Crafts" training (German model, time/amount of loan limited, repayment of loan takes precedance over any other private loan by law)
- change of the electorial system to a more direct democracy, German 5% rule for new parties in federal congress, implementation of 'election zones' based on fixed amount of citizens (nationwide) ...
That's all I can come up with now, but it would probably solve 90% of the problems in the US today.
My 2 cents.