Hi a_rotar,

Welcome to the forums.
You should use or alter the _atom or _rss skin in the skins folder.XML is a broad and flexible pattern so I can't tell from here how you want it to look.
You want to alter the number of posts / comments. Do so in the skin (I am not sure if you can set it there) or in Blog settings -> General.

If you have subsequent questions please report back to this topic.

Good luck

THX,

worked fine, I managed to get the xml as I wanted.

Have a nice day.

Well done.

Happy blogging