its not a problem your comment should be related to site ans theme dont just comment like this. your comment should make sense.
using the keyword instead of your name can lead to your comment being deleted, depending on teh keyword it can look spammy
Haha I find it funny nobody gives complete answers! Blog commenting is a great way to get back links (as long as the blog allows for them). But you need to remember how to really do them. Don't just go around spam commenting on every blog you see, even if they're not related to your product niche. Find relevant blogs and write relevant comments that actually add value to the web.
some blogs has no follow so they don't restrict you to use keyword as your name but some restrict you . but still there is lots of blogs allow you use keyword but as above poster said , your comment should be related and the point . no copy past or spam .