Magento Expert needed for trouble shooting and fix

We have some issues after upgrading theme and extension to new version. 1. Trouble shooting and fix . modification for integration of shopping cart, checkout, and account login. 2. Shipping cost set-up We want to change shipping cost rate. 3. Extra fee set up for optional service. 4. Additional Minor work. Adding some images, etc. Detailed description provided to candidates. Magento Expert only please.