I feel that most of the restrictions you propose would reduce the pool of aspirants to political office to a level only very slightly north of zero.

Which is fine.

Most societies would probably be better served by a technocratic civil service proposing alternative measures on which a randomly selected (statistically corrected for representativeness) and rotating group of citizenry would vote, have received learned explanations of their implications and consequences.

Essentially jury service on a national policy scale.

I don't think it could be any worse than the typical democratic model in most countries, and would expect it in fact to perform rather more beneficially for the majority.

The ceremonial head of state could alternate between celebrated film stars and athletes.