OK, I start with 3rd, because I have nothing to add to the first two points:

Ban selfvotes!

Sure, but often the biggest abusers also have the biggest number of different accounts ... Maybe something like 'diminishing returns' when upvoting the same accounts (also own one's) again and again would be more effective?

Forbid buybots and “vote for delegation“!

How do you want to 'forbid' that in a decentralized network?

I would say: flag posts upvoted by bid bots, and it's not worth anymore to pay for them! That's one thing that works rather well already on HIVE in my opinion.

Reintroduce the open/read posting counter!

Well, maybe only count these visitors who stayed at least for a certain amount of time ... But right, I agree.