Ripple/Stellar are a real crypto,
wrong
ripple:
cryptographic secured transaction: no
blockchain: no
decentralised: no
This is wrong.
Transactions are cryptographically signed and secured, otherwise anyone could access anyone's balance...
Blockchain: Yes, however unlike Bitcoin (which only stores a transaction tree in blocks) Ripple stores the AccountState (comparable to the UTXO set in Bitcoin) AND transactions in it's chain. This means bootstrapping is easier, as you only need a recent "block" (aka. ledger), not every block from the beginning.
Decentralised: It depends. I would agree to a "no" for now, it is built to be decentralised though from the start. It is not clear what you mean by that term though, in your comment about stellar you write something about gateways, whcih doesn't make any sense.
Since Stellar is just a fork of Ripple, the same is valid there.