Magento, Apache, Htaccess, Javascript Task

We recently moved our website from one server to another server. We are currently having issues: 1. Adding items to the cart (could be due to javascript, uses AJAX to load, but just says loading and doesn't add anything to the cart) 2. Somewhere in our htaccess file we have a rewrite rule that is forwarding to the non www version of the site (i think). We need the site to always use www.domain.com. (fixing this issue should/may fix the adding to cart issue with AJAX mentioned above in issue 1) Setting the Base URL in the backend to [login to view URL] did not fix this issue. 3. When cache is turned on, there are issues. Not sure what issues since i'm afraid to turn it on. Would like that to be looked at. 4. When trying to sort orders, or go to the next order screen within magento's back end (admin) it just says "please wait..." and keeps spinning round and around, and doesn't load anything. Budget is $80. Please DO NOT bid if you cannot complete tasks for that amount of money. Anyone who bids lower and gets accepted, to only raise the bid later, will be dropped. NEED an expert in Magento and server related tasks.