I know why people decide to use captchas. However, it seriously puts a damper when wanting to leave a comment. So much to the point that if I can't get the damn thing within three tries, I just leave the blog. I hate doing that cause I want to comment, but I just hate figuring out what the crap those letters are. Not all are horrible Some are pretty simple while some, no matter what, it just isn't working. So in my personal opinion, say no to captchas!
The next thing is the no-reply bloggers. I know we all love getting comments and sometimes, it's just nice to reply back to what someone has written or address a question they ask. But of course, I find it difficult and also a bit frustrating when I go to type up my response and it can't be sent.
And then that is it. I believe blogger defaults to no-reply and you have to manually change it this way yourself. At least that is how it was when I started. Having your email show is just a lot easier to get replies and having a way of communication back and forth.