The longest run up until now... But you shouldnt be so sure that it is still a democracy and you shouldnt be so sure that the fact it was kept a democracy for so long was because of free speech absolutisme. I for one, think that the US of A has lost a lot of its narrative in the last 20 years. I think its the narrative that kept it a democracy until now.
Not the longest. The longest is San Marino - since 1600.
What's with the Vatican?
Not a democracy, an elected absolute monarchy. More akin to the prince-electors of the HRE.
it's a democracy, without universal suffrage
like the US until the repeal of the Jim Crow laws (1960s)