Chnage and Improve a platform that creates a 3-D home design

Must be experienced in 3-D imaging and JavaScript. Want to see sample of you doing similar work. I have a online home and office design rendering platform, see bellow: [login to view URL] I want to combine the functions of this site: [login to view URL] to mine. I also need the following: 1. The platform is currently running slow on loading pages, i need you to adjust it to increase loading page speed. 2. All the changes you made must be mobile friendly. 3. Must change to allow users to register with a username and password and they get an email confirmation and once register they are allowed to make and save their own design in their own account. 4. Need a dashboard / control panel that control all functions to the site. The dash should control: • for the admin that allows admin to remove or add the furniture's that are listed on the "Add Item" section. • to control user name and password access. 5. the dashboard should have a easy to use buttons to allow admin to upload furniture or equipment image or remove the pre-existing furniture. 6. If the user wishes to do multi-level design, where stair cases are required, i want the platform to allow option for user to select number of floors and to allows user to design multiple floors and place stair case or elevator as needed to any location. 7. I need to be able to change the flooring design also.