1.Is it a cryptocurrency?
2.Does it have blockchain?
2.Does it involve Trusted Third Parties?
4. What is the inflation rate?
1. It is a decentralized exchange running on a custom blockchain. It includes a native token, called XRP which can be called "cryptocurrency".
2. Yes.
2(!?). Yes, every token besides XRP is issued by a third party that you need to trust.
4. Of XRP? That one is actually negative, as all of them are already created and they get destroyed for transaction fees. However, most of them are still owned by Ripple the company, so when they sell/distribute some, this might be viewed as something similar to inflation or have similar effects on the economy/ecosystem. How they distribute their XRP tokens is up to them.