First reactions on this:

1. It basically implies that people who have more imaginary points like badges and followers are worth more than those that don't. It will incentivise people to accrue more badges and followers, not because it it nice to have, but because it leads to something else. The equality that is the foundation of hubski's comment section, where it matters more what you say than who says it, is one of the strong points. Any new user can post a comment and will have just as much chance at starting a discussion as someone like kleinbl00.

2. Maybe do it similarly like Facebook? That if you hover (not click) over one's username, that you get to see their bio and maybe a snippet of the rest of their profile. It needs to be quick above all, that you can instantly see more of who the human behind the name is. And people already have their bios setup, with pictures or not. I like that more than having a gaping hole if you don't want to have an avatar. Besides, most are shit anyway.

Here's a snippet from my comment in that discussion in the Unfollow Guilt topic that I think is relevant:

Let's get our goals clear. What I think the site will benefit from is a better way to foster relationships and connections, both existing and new. One way this would be achieved is to make them more recongnizable, e.g. avatars / images / anything visual.

[...]

A way to foster connections is through the information you can know from someone else: right now I can only see how many posts I shared of you (19). It is where my idea for previous conversations comes in. There is a plethora of data that you can show to others. Which one is valuable is something to think of. Preferably, viewing someones profile, you would be able to assess who they are in relation to yourself.

3. Sounds like a good idea. It makes people discuss more, but a possible downside to this is that people won't read the article anymore. Especially if someone highlights one important paragraph. I prefer it when someone does that, don't get me wrong, but I'd rather see that after reading it. It might negatively influence my article reading, but it is good for discussion nonetheless. Really depends on the direction mk and others want to take the site to.

4. If you impose limits, there will always be people trying to work their way around it. If you have to comment 10 times, they will post ten comments with one letter, then submit their spam post. I'd love to hear how HN combats this problem.

One thing I don't like about the old forums is that they have the problem of people talking parallel. If you center a community about a topic, people will comment about that comment and not respond to each other. They say their thing about a subject and barely get responses or respond to people above them. While we're not a forum, and have a much better environment to hold discussions, it is definitely something to keep in mind.