Hi,
1. For pricing table you should use a plugin that best suits your taste. Here you can find some free ones http://wordpress.org/extend/plugins/pricing-table/ , and here are some premium ones http://wpshock.com/wordpress-pricing-table-plugins/
2. Please add this to the bottom of /css/custom.css or to Quick CSS located in Choices > Theme Options > Styling .. text box at the bottom of the page:
.main_menu ul:first-child > li.current-menu-item > a, .main_menu ul:first-child > li.current_page_item > a {
font-weight: normal !important;
}
3: Please look here for instructions http://www.designchemical.com/blog/index.php/jquery/using-jquery-to-validate-search-box-input/
4, Hi, I apologize but your instructions "change the font size of heading font of custom heading but not of display this entry heading" could mean a lot of things. Please provide a url to the page in questions on your website, or a similar page on the demo http://www.kriesi.at/themes/choices/template-files/ site, including indicating which phrases are custom headings and entry headings.
Thanks,
Nick