Hi and thanks a lot for your review. A few notes:
1. What do you mean by non fludic main column? The theme is responsive and will display accordingly on mobile screens. It will also rescale with the browser window should you play resizing that. It doesn't scale over a certain value that you can choose from the theme settings, so if you choose the width of the site to be 1100px of course the main column won't be fluid. It will be 1100px unless the browser window is smaller.
2. The continue reading button will actually shrink a bit in the next update.
3. Infinite scroll is achievable through use of Jetpack (as many other themes)
4. The searchbar, if used in the header widget area will require some CSS from your part so that it can be placed anywhere in that area. Should you choose to place the searchbar in any other widget you'll see that it fits nicely.
5. What more would you like to configure about the top menu? Just like any other menu in any other WordPress theme you can configure it from the WordPress dashboard >> Appearance >> Menus. Here's more info on menus: http://codex.wordpress.org/Appearance_Menus_Screen
Have a great day!