can i download and install these daily build ISO files from here?
i think these are same standard ISO files with update patches only and are safe to use. right?
They're probably fine, but as with all "daily" images, there's little testing and absolutely no guarantee that it will work properly. Ongoing attempts to fix one bug can sometimes break other things, and these issues are often not fixed within a single day.
Feel free to try it out, but keep in mind it's totally at your own risk, and it's possible some things won't work properly. But it's probably fine.