We should aim for meritocracy but encourage participation and discourage demeaning action (downvotes) which drives away participants.
Downvotes are a feature that was added for a reason: the same reason as why we have upvotes: good content is voted to the top. Votes are a privilege reserved for users who have been around for a bit (15 rep for upvotes, 125 for downvotes). This helps making votecounts reliable.
Those voting 68.26% or more in either direction should be discouraged from further voting as incentive to balance once's voting.
There already is a limit to how much you can vote on a day (40, I believe). There is no need for a further limit.
Answer votes, up or down, must be explained with no less than, say 12 characters - e.g. "+1 for clarity" or "minus one because your premise is an assumption"? A warning prior to disincentive (minus points) seems a good idea.
This has been suggested many times for downvotes: 1, 2, 3, ... I will not repeat the reasons for why this has been declined here. I will add though, that often enough reasons are given.
For upvotes, I don't see the point: first of all, justifying upvotes will give too many comments and that will just clutter up the page. Secondly, the reasons won't be very inspiring. People will just add "+1 because it's true.".
I don't see why we should warn first and then downvote. When the post is edited, the downvote can be undone anyway.
Likewise, those providing 68.26% or more questions than answers (and vice versa) should be discouraged from further questions or answers depending on how their actions are skewed. After all, what philosopher out there provides answers only? None.
You seem to miss the point that the users here are not philosophers here. They may be somewhere else, here they are people discussing philosophy and well known philosophers (possibly including themselves). Would you suggest that Jon Skeet can't add answers anymore, because he doesn't ask many questions? We'd miss a lot of good content.
Stack Exchange is a good platform, but you need to learn how it works. For this, the Tour was designed for new users. Please go through it, because it will help you understand why the suggestions you made don't fit in. A more extensive help source is the help center, and ultimately you can ask questions here on Meta.