You are an extremely valuable contributor to HN. Reposting your HN comments is great way to start blogging. I think you will eventually feel the urge to post original content once you see how rewarding blogging can be.

1-I would leave comments on. You never know when someone might have an extremely valuable tidbit to share.

2-up to you. 20 is as acceptable as 100.

3-Not lame

4-cool