node-libs-react-native | Node core modules for React Native | Runtime Evironment library

Unfortunately as you have quite rightly identified you cannot use that npm package with react-native as it does not have the https module.

However, looking at the package oxford-dictionary it is a single file that provides a few helper methods to construct specific network requests to the Oxford Dictionary api.

It wouldn't be too difficult to re-write these in terms of fetch and make your own helper file. You could even create your own react-native package for the Oxford Dictionary api and publish it to npm.

With regard to accessing the Oxford Dictionary's api, there shouldn't be an issue doing it as it is just network requests. fetch should be able to cope with it. You just won't be able to use the oxford-dictionary npm package to make the requests.

The problem is that the eth-lightwallet depends on node core modules that isn't supported by React Native out of the box. The current workaround involves using rn-nodeify in order to provide shims for React Native to use instead. See this issue for react native and see this open issue from eth-lightwallet.

No. There is no reasonable alternative for Node's fs.readFileSync.

Though technically it is possible to write a readFileSync shim that blocks on an asynchronous file operation, it is inadvisable to force synchronous behavior in an asynchronous system (but you may be able to get away with it, when only having few synchronous methods in one-time initialization code).

So option 3 or 4 are the only viable alternatives.

In my case there were too many Node dependencies, so I ditched browserifying / shimming and opted for 4. But ...

That does not mean all is necessarily lost. I am now investigating Compiling NodeJS as native library in Android

(And Realm.io to bridge native NodeJS + React Native in Android fat client app (CQRS-style)).