Drupal login/register form customization and error fix

1) I am getting a Drupal error "The file could not be created." when I try to activate the full CSS optimization option under Performance in a Drupal site. 2) I would like to customize the login / register / forgot password for a drupal site. Currently it shows the default 3 tabs on the user/ page, I would like 3 separate pages instead. Similar to this but within the drupal site template: [login to view URL], [login to view URL] and [login to view URL] I want it styles the same way and the text to be changed (more details to come). I also want the terms added just like the Twitter terms. 3) I have a form that has inputs for the fields bellow. They each have an input and a select list. ie. Distance as an input and a select drop down list with ft/m. I want the user to be able to set their preference in their profile so that when they go to this form, the preference is already selected. So if bar is their preference for pressure, bar will be the default selected in the drop down list. Here are the fields: distance: ft/m pressure: psi/bar volume: cubic foot/liter weight: lb/kg degrees: F/C 4) move the search box into the menu such as found here with ajax keyword drop down: [login to view URL] ------------------------------ - All changes must be done using proper template and theming for Drupal (not editing the core Drupal files). - There should be no interference with the current live site, therefore everything should be done on a copy or duplicate of the page