URL to your site?

The page that you see after clicking on "read more" is created automatically by K2. If you need to have a short introductory text before that button though, you also need to split your text into introtext & fulltext. To do that, either use the "read more..." button in the WYSIWYG editor OR go to K2's Settings and under the "Advanced" tab, choose to have 2 editor windows (instead of one).

This is just CSS styling to emphasize the introtext. It's by design, not by mistake or bug.

Of course you can. But you obviously don't understand what "CSS styling" means, so you should have a professional deal with your site as you're bound to face other issues as well in the near future.

That's great - he should be able to spot such issues in the future then.