I suggest three changes: (1) like you, repeal the 17th Amendment, (2) Eliminate the need for 2nd Senator from each state...just go with one, and (3) eliminate any connection of the Senate to the budget.
The only basic functions that I think the Senate ought to be covering: approving cabinet officers for the President, voting up or down on treaties, approving court appointees, and impeachment situations.
If we did these....then you wouldn’t have the whole Senate behaving like lobbyist-controlled nutcases.
That sounds like the Governor's Councils found in some states.
They don't have much power or visibility, but they do give eccentrics a chance to run for office without doing much harm.
I don't think the writer's plan would work. It would do a lot to remove a check on the power of the House and the President.