1. Go to Page Settings for the page and check the box to show breadcrumbs and/or child page bread crumbs.
2. go to the main site, Administration > Site List, click the child site, there you will see a tab to add features to the child site from the list of available features.
3. The built in contact form has limited settings (click the settings link next to the title of the contact form), if you need more flexible custom forms consider our add on product Form Wizard Pro, you can try it on our demo site.
Hope that helps,