Don't use Proton. The owner of the company is a Trump supporter. Also, Proton is based in Switzerland, I think a EU service is better for European citizens.
I don't want to ruin your day, but Proton is not a safe service anymore, after its owner publicly expressed his love for Trump. So, I highly suggest you to try and move to another European service such as Posteo or Tuta.
Labels are displayed as folders on IMAP, which means that a single message could appear in multiple folders. Are there any other problems you're talking about?
When I was 16 I would have totally posed for porn and I would have been completely consenting. But it would have been illegal. I wonder where we should draw the line, and if the current one is the best one.
I think we would set a better example if more people went the Mario's brother way.