With VPS Hosting, you have complete isolation. This means that no matter what other users might be doing on the server, your VPS package will be unaffected. With root access, you can install whatever applications you require. VPS also gives you guaranteed resources, so no matter what, the CPU, RAM, Disk Space and Bandwidth allocated to your VPS package will always be available for your applications. It gives you all the features and functions of Dedicated server, without the additional cost.
Yes, with every VPS you will receive one dedicated IP for free. You can raise a support ticket to get additional dedicated IP.
No, VPS are not refundable.
You are responsible for your backups and web content. It is recommended that you keep copies of your content safe and make your own backups. You can take a backup from your cPanel or use a remote backup solution.
You can upgrade the VPS, but downgrade is not possible with any VPS plans.