Upgrade Magento to Ver .2.0 and fix some issues with current site.

We have a nearly completed Magento site at version 1.9 and would like upgrade to 2.0 and fix some issues (below). Site must be built in a test development server environment to test so that current site is not damaged. First, all extensions applied must be evaluated and tested to work with Magento 2.0. All UI should work as is with 2.0, we do not want loss of features or look including responsive. All database must be migrated from current store to 2.0. Current site is at: [login to view URL] Issues with current site that need fixing: 1. Search does not work properly. It was working fine with a preview at one point but work from another developer broke the search and they were unable to fix it. Search should show preview as with installed extension and find products with no problems. 2. Minor CSS color changes with UI. 3. Tab for free shipping at bottom of screen was working fully at one point and was also broken by other developers work. As items are added to cart, it is supposed to show remaining amount to total $75 in cart for free shipping. As currently, it does not update until you navigate to another page instead of on add to cart. 4. Site speed was very fast at one point with compression and FPC. Work from other developer has slowed it down. It may just need to be optimized again. Front page was loading at under 3 seconds at one point. 5. Minor UI adjustments such as <> scrolling on YOU MAY ALSO BE INTERESTED IN panel for responsive cel phone size product listing, <> overlaps header text. Thank you.