You do need better democratic oversight than you have in the USA cough in my opinion.
So have multiple independent unions that have each other on speed dial for when they need to amplify influence. And lobbying should be opt-in by individual members on a cause by cause basis.
2 Again in the UK there are very heavy restrictions placed on union lobbying and I suspect in the USA to.
I am sorry balloting members individually on every policy is madness that's what conference is for.
We have technology for this, and it's not hard to take a vote. I will never be a part of any union that presumes to speak for me on individual issues without my individual consent. And if the union is doing so many things that the number of votes are too much for individual members to deal with, it's doing too much.
(By contrast, it does seem entirely reasonable to give broad parameters to people doing negotiation, rather than doing negotiation ballot by ballot; the members should then vote on the resulting negotiated proposal, though, before it gets finalized.)
I like it this way better because it gives you the ability to have more control over the organization as a normal worker. All that scary "union dues going to big bad bosses" rhetoric goes out the window when you know the union leadership as your co-workers.