What are the storj coin's values? i can find nothing from the website

Storj tokens are utility tokens, not investment into the company. They are used to pay for the service and as a payout to Storage Node Operators.

Of course it can until their datacenter would not have issues, as it was presented many times. Storing only in one datacenter is not safe for data. The repair and audit also absent for IPFS (but may be supported by pinning service though, however you need to figure out that), by default it also unencrypted and even not distributed as pieces, it’s a whole fully readable for any node operator. So you cannot store any valuable or private data without an encryption made yourself before upload, and decrypt it later when you need access it again.
They also suggest to use a replication between different providers to have a redundancy, but it’s again up on the user. If you are not familiar with their technology and caveats you likely could lost your files.
But replication is a worst "solution: actually:

Please avoid posting an advertisement links next time.