[izacus]

RxAndroid does bring some overhead due to you having to create alot of anonymous classes (lack of Java lambdas really hurts here).

Butterknife and Dagger both use compile-time generation, so they're basically free and make your app well structured. I really wouldn't avoid 3rd party libs in your position, using good ones will make your apps less buggy and will let you easly create way better UX for your users.

For example, EventBus (or Otto, both do the same thing) is pretty essential for coupling things together and keeping them working over orientation and other configuration changes. I've seen so many apps locked into portrait position just because devs couldn't figure out how to decouple model from views and keep the app running over orientation change.