Comments? And, can I modify the core functionality?

Hi everyone.

First, sorry if my english is not very Understandable :/

I will start to publish my webcomic in short, and I am looking for a platform like this. Right now I am using Wordpress, and I tried with ComicPress theme and Comic Easel plugin, but I am not very happy with the result (Mainly because it feels like a patch after patch, and too much functionality that is not needed). Then, I found this CMS and looks very cool and simple, I want to try this. But, I checked the sample sites of other comics, and I noticed that all use Disqus for the comments in the pages (Or simply have no comment), and I don´t like Disqus very much.

So, my first question is: this CMS have a native option to comments? If not, are plans to implement this in the future?

In other theme (a little related), can I modify the core code to add some functionalities (like, for example, comments)? My "human" job is Web Developer in PHP, and I want to know if is acceptable for you that I modify your code, or added more modules.

Final theme (for know), how this run in performance and speed without a cache plugin or something like that? I ask because my actual Wordpress site is a little slow, and I needed to install a cache plugin to Improve performance, but I understand that here it is not a option (not directly in the platform, at least). So, do you think that the performance is acceptable without it?

Thanks for your help and all your work :)