You are free to classify or delete comments posted against your blog - but comments posted against somebody else's blog are their business, and their opinion.
With Google+ based comments, moderation is a community exercise. Anybody, seeing an abusive Google+ hosted comment or post, is able to "Block" and / or "Report abuse".
You, the blog owner, have no special responsibilities or rights, with regard to comments posted by someone else, against your blog.
Comment moderation is a community responsibility, with Google+ posts and comments, and with Google+ based comments against Blogger blogs.
- You cannot, unilaterally, declare a comment to be abusive.
- You have no need to spend your time reading comments, and deciding if they are abusive.
Any Google+ member, seeing an offensive post, can mark it.
Everybody has the ability to mark any Google+ post - or Google+ based Blogger comment - as abusive. You can do this, against your blog, as well as against someone else's blog.
You, being a blog owner, have no unilateral decisions to make, to delete or to mark any Google+ post or Google+ based Blogger comment - even if the Google+ post mentions your blog (Google+ based Blogger comment is against your blog).
You can't view every comment or post - even if your blog is mentioned.
If a Google+ post or Google+ based Blogger comment is not published to the public, by someone who has not circled you, you won't even see that post or comment. With this lack of visibility, community based moderation is the only possible solution.
You have no need to read each comment, one by one, and decide if it is abusive. This eliminates the need for individual moderation - and allows all comments to be published, immediately. As a secondary effect, this encourages more comments.
You can spend more time working on your log - and let your readers moderate.
Since you don't need to spend your time reading comments, you have more time to work on your blog. This gives your readers better / more content to read, and encourages more search engine traffic. More search engine traffic leads to more readers, and more comments. Eat, sleep, rave, repeat.
Community based abuse classification allows more accurate and prompt feedback, into the Blogger / Google abuse classification processes. This may help reduce the volume of spuriously classified blogs, reported in Blogger Help Forum: Something Is Broken
Why was my blog deleted? I don't spam!!As a secondary effect, Blogger Policy Review may be able to more promptly review the blogs that are reported.