Uber like App on blockchain The Project Model How to build one

Question

Suppose I wanna launch a uber-like carpooling app on the blockchain then what would be the project model.

I'm fairly new to blockchain so I'm trying to understand Its implementation via examples.

Here are my few assumptions, and I want people to correct me if I'm wrong.
 

As blockchain can be thought of as a decentralized database(I know it's more than that). If we think of Uber's database, there must be some DB table for drivers, where they have their profile, location, ratings, etc infos. Same for customers, they'll have their profile, previous rides etc.

assumption 1: So for drivers and customers to exist on a blockchain (let's say, the Etherium blockchain) they first have to create a profile and they'll get a public key and Private key and they'll become a node on the blockchain (right??). Next, they have to submit all their data(like profile info, car number etc). And all those data will be stored on the blockchain. To store profile related data for both drivers and customers, there should be a smart contract, which is written in a way, where It can keep data related to a person, and that data can correspond to the public key of the person (customer/driver).
My question is this the correct way that I'm thinking. by doing this won't all the data of a person can be visible to everyone (maybe that's the point)

assumption 2: There will be another smart contract that can be invoked by the customer when they want to ride a cab. that smart contract takes multiple inputs like the customer's location, destination etc. Then It calculates a fee and finds any drivers near the area. Also, the fee can be agreed b/2 the driver and the customer also.

assumption 3: After the ride, the customer can give money to the driver from the money in their wallet.

I want to know IF there should be an app like this, the assumptions I'm making on the blockchain model, ARE those correct??
can anyone help?