Questions

NetCells provides hosting since 2003 - we now runs multiple servers, in various locations - private (vps) and shared. You can duplicate your data on two or more servers - in different locations.
The data backup depends on the server - but all have automated backup (in another location) in case of a failure - that limits the data loss.
That said, remember that, due to the very nature of the Internet, there is no absolute guarantee against data loss. You are advised to keep a copy (or - better - copies) of all your valuable data.