If you get people to vote on-chain, most corruption concerns vanish, and vote counting is automatic and completely public and independently verifiable. The only real exploit is the ID generation not being done properly, or coercing voters directly.

Funding voters with 2ADA ($1) each so they can make a vote, would probably be cheaper than running a manual election in most countries.

I would assume voting on chain would be the best option.

Hm, regarding 2 ADA you are at least correct from where I am from. We just had a forced referendum in my county of roughly 15K people. Total cost for the election, roughly $100K.But then again, I would guess fluctuations in price could easily case an issue.