Change a few things on modified oscommerce shop

For a new webshop, i need a few modifications done. [login to view URL] -The log-in page should be shown before going to the shopping cart (in any possible situation). -Orders below 250 euro have an extra cost: handling cost = 5 euro. In the client-section in the administrator, 2 checkboxes need to be added. The administrator needs to be able to cancel the handling cost and the shipping per customer. -Checkbox for "no handling cost". No handling cost may be applied if this is checked. -Checkbox for "no shipping cost". Any shipping cost from the available shipping methods must be overridden if checked. On the create account page: -The fax can be replaced with cell phone number and can not be a required field. -Change a few colors in the shopping cart and remove some text. (details will follow)