I would suggest then you use a different theme that pushes the content further up.
You can disable commenting on your posts, but completely removing the three you mention isn't an option on a free theme and, if I may be blunt, your visitors will not loose attention by having them.
I noticed that you're using your pages as categories.
WordPress has the ability to add categories to posts, so you can have many different entries under several categories at a time.
Let's say you're writing a post on a Zen Toolworks CNC.
You can put this post under the "CNC Machine" category.
Or if you're writing about resistors or transistors, you can put it in the "Electronics" category.
Or if you're writing about a Canon DSLR, you can put that under the "Photography" category.
Pages should be reserved for "pages", not categories.