Sapphire enables far more than just private transactions like tornado cash. Sapphire dapps can be entirely public or entirely confidential as well as the entire spectrum in between. By giving developers the choice of which aspects they wish to hide they can build dapps that best suit their respective needs. For example a dex could hide slippage parameters while keeping all trades entirely public they would be able to be MEV resistant but still entirely public. We expect that these are the type of use cases the majority of dapps built on sapphire will target

Node operators on Sapphire are required to run trusted hardware which acts as a black box so that even they can not see the confidential data. Other than that the network operates in the same permissionless as any other blockchain network

It is extremely easy. Sapphire is almost entirely EVM compatible. Here is a step by step guide to deploy your smart contract on sapphire https://docs.oasis.io/dapp/sapphire/quickstart

Rose by default is entirely public on Sapphire. In order to do this you would need to create a wrapping contract which hides this transaction data.

Monero and Zcash are “privacy coins,” concerned with facilitating anonymous and untraceable transactions. Instead, Oasis is focused on data privacy, supporting applications that need to process sensitive data. Privacy coins serve an important, but narrow purpose. Confidential paratimes can support a wide range of use cases beyond anonymous transactions.

There are some big differences compared to each of those, both in the overall architecture of the network and the security design. To start, let's first explore the overall architecture to highlight how confidentiality is being protected in the Oasis network architecture. On a high level, the Oasis network introduces a notion of ParaTimes which are their own blockchains sharing security with the consensus layer. The consensus layer itself is not confidential and does not support user-uploadable smart contracts. Its core function is to manage everything that is needed to support ParaTimes. In stark contrast, Monero and Zcash are privacy coins at the consensus layer and do not aim to support general confidential smart contracts.

Sapphire uses TEEs to compute privacy. The major difference from Secret Network would be that Sapphire is EVM compatible allowing for popular developer tools like Truffle, Hardhat, and MetaMask.