Can I move from shared to VPS without downtime?

Yes, with a planned migration: copy the account, test on the new IP, then switch DNS. Open a ticket and support handles the cPanel transfer.

Is a VPS always faster than shared hosting?

Not automatically. Shared plans run LiteSpeed with caching tuned by us; a badly configured VPS can be slower. A VPS wins when you need dedicated resources or a custom stack.

Do I lose cPanel on a VPS?

Only if you choose not to install it. cPanel needs a licence; CyberPanel and HestiaCP are free alternatives. See how do I install a control panel on my VPS .