If I were to do something about Google Plus Comment system I’d do the following.
Before talking about doing something the factor that I find missing in the Google Plus sharing and comments system is integration. I share a video on Youtube, Youtube has it’s own share of comments and the share on Google Plus has its own.
I’d replace the comment system from Youtube, Blogger and all other Google platforms with Google Plus. Whenever one shares a video or other items, the comments will also get included. So the video and comments will act as one entity rather than separate ones.
Like Disqus, I’d add these tabs,
The first four are self explanatory. The fifth tab, “Your Share” will show only comments generated from my share. And the sixth tab, “Your circle” I think is the best one. This will show the comments from all my circles or the circle I choose. It would be nice to encounter a share and see if some of my friends has already seen it and start conversation from there.
Naturally the 500 comments limit has to be taken off for this and pagination should be added. The comment system should also have reply support.
This also implies to all the re-shares of post in Google Plus itself.