Add finishing touches to Magento website

The Person who put the website together has disappeared so I need someone who clearly understands Magento to finish a few things on the site to get it looking and performing 100%. 1. I need to add a surcharge when someone pays by Credit Card, (1.5% for Visa/Mastercard, & 3.5% for Amex). 2. I need to incorporate a specific freight module into my site that calculates the freight using the cubic measurements of each item on the order plus the delivery postcode, (I have the API but dont know how to load it). 3. I would like to be able to change the colour and feel of the Home Page myself from time to time so as to freshen it up. 4. I want to incorporate a Voucher/Coupon system, (if a registered person recommends a friend, and that friend spends $100.00 with us, the person that recommended them will get a $20.00 Voucher to use on their next purchase). 5. Gift Cards...I want to have a facility where someone can go into the site and BUY a Gift Card for set values of $20/$50/$100 to give to someone, (they would be able to Print it up and get a specific Gift Card number that we would also get so that the Gift Card is only used once and will alert us if someone tries to use the same card twice. 6. I would like you to suggest and implement a simpler "Registration" and "Log in" method to avoid confusion between my "public" and "Business" customers, (at the moment, I have many businesses that inadvertantly register as consumers and I have to change it from the admin section). 7. I want to be able to run regular Specials and use the "Specials" banner that is currently there...I need you to show me how to use it or make me a simple one to use instead of it. 8. I need someone to show me how to upgrade Magento as needed without affecting my settings or any modifications that have been made. 9. I want to consider adding some "unlicenced" background music to the site without slowing it down.... Latino instrumental music most likely best option. 10. Speed up the loading of the site...It currently takes too long to load and I think it could load faster with a littler professional tweeking. 11. Advanced SEO Optimization so that we get more traffic through the site.