I do like the sortition method, for certain offices. Randomly pick a dozen or two for an office, then let them make their case to the voters.
Term limits also seem fairly necessary, career politicians don’t seem to serve any interests but their own.
As we have seen over the last 4 years, we do have a deep state. An army of bureaucrats that actually keeps the engine of the government going, with the elected officials simply calling out the direction to go, rather than how to get there. The people in office do not need experience, they do not need networking and connections, and in fact, those seem to detract from their ability to meet the needs of the people that they represent.
My ideal government would have substantial redundancy. Rather than a bicameral legislative branch, a pentacameral, with each house being nearly equal in power, but having its own way of selecting those who are in it. One house to represent states, like the senate, except with 3 from each state, one every 2 years, they can be appointed by the state government, or elected by the people, up to the state to determine; one similar to the house of representatives except the representatives elected at large and a much larger body, one for every 50,000 residents; also, add in a house of meritocracy, where you do have to pass a test in order to vote for the members(the test to be written by the members of the house itself); a house of proxy votes for a direct democracy; and a house of plutocrats, where the wealthy bid against eachother for seats(with the proceeds going into the general fund.) Any 3 houses can pass legislation with majority votes of their own, subject to veto, which requires 4 houses to override.
The presidency should have much less powers than it does. It is there to enforce the laws of the legislature, it is there to follow, not to lead. That said, how laws are enforced can be a matter of interpretation, so should also be subject to selection from the people. I recommend a triumvirate presidency, where the top 3 vote getters having nearly equal power, mostly in the power of veto, any one can veto a bill and send it back, with the top vote getter only a nominal position over the other two. They’d be the one that lives in the white house and makes the speeches, but the other two would be able to override or take power if they agreed with eachother. They would also serve as back-ups, in case the top is incapacitated for some reason.
Scotus Judges should be appointed by either the top executive, or the two lower executives, and confirmed by either the senate and one house or three houses not including the senate. No lifetime terms, a long term, well over a decade of 15-20, maybe even 25 years, but not lifetime. At least one’s term should be ending every 2 years. They should be in charge of the lower courts, nominating people to fill those positions, requiring only 2 houses and one of the executive triumvirate to confirm. The lower courts too, should have long but not lifetime terms.
All voting for candidates should be ranked choice voting, with the plurality being the winner. I would use sortition to select the candidates to run for the positions of the house of representatives and the executive triumvirate.
Money is not speech. People may not spend money, or donate money for political advocacy. You may spend up to a month’s median average wage on material or your time and skills to advocate for a candiate you prefer.
Well, either all that or just make me dictator for life, I promise to be benevolent. 
All that said, as has been pointed out, we get the government that we deserve, that we vote for. I think that my system helps to remove some of the dangers of underinformed or even malicious voters, but ultimately, if you want a democracy, you need an educated and informed populace.
Education does need to include far more critical thinking and political science than it currently does. News needs to include far more boring policy wonk material, and far less sensationalism. How to accomplish those is a harder task, probably, than reforming the entirety of the government.
. The combo of Prop 13 and the super-majority rule make it more difficult for local communities to properly fund services and local infrastructure. I might be fine with a lower super-majority level like 55% or something, but I feel 66% is too high a bar.