influenced other views on the same page

You have a good point this should be for this views not all views. The CSS is too generic. The offending CSS is here in the inline_comments_views.css file:

.views-row {
background: #eee;
margin: 2em 0;
padding: 2em 2em 4em;
box-shadow: 3px 3px 5px 0 #ccc;
border-radius: 5px;
}

For the moment you can override this in your own css files in your theme. I'll work on a way to add this just to inline comments views with more specific classes.

I made a little patch for this.
But I don't know what is exactly '.user-signature' ?!

@kitkat13, .user-signature shows when you activate User signatures in Configuration / Account Settings. The signature is then displayed with the comments.
It may not appear in your case because signatures are disabled.

Also, this patch relies upon CSS3. Ideally, the css should be cross-browser and backward compatible.

@madmatter23, I don't see how the patch relies more on CSS3 than the original code, am I wrong?

You're absolutely right. I hadn't really dug into the module yet. My comment applied more to the original module than to your patch . I'm running through it and making a bunch of modifications.

@madmatter23 Don't hesitate to post a sandbox if you have something better than the current module (and its mandatory patches...).

I spent about half of a day making some substantial changes to this module, but I eventually decided to scrap the whole effort. This module does a bit too much 'reinventing the wheel' for me.

Instead, I patched the Ajax Comments. module:
#1711476: Views integration

I've added ajax integration for the Views 'add comment' field, which is the aspect of Inline Comments that I needed. I may go on to add 'View Comments' field, but I don't have plans to do it immediately.

supplement