I prefer eclipse over android studio, my question is if I can still use it to build projects for future development - for example the recycleview library. It is supported in eclipse too, but will future google libraries continue to support it?
In the end, it is all just Java, XML, and other such resources. The RecyclerView library is no exception- it is just a library that can be used in any IDE.
The IDE you use for development is just a tool to view and edit these project files. Separately, you use a build system to build the application. Your IDE, the build system, and the project files are completely separate and one doesn't depend on the other to create a functioning application. In fact, you can build an Android application without an IDE at all.
The biggest issue you might run into here is the format of libraries such as RecyclerView. In the Eclipse days (note that Eclipse Android projects typically use Ant for building), most libraries came as either JAR files or Android libraries (of source code). With the release of Android Studio and the Android Gradle plugin, everything is shifting towards Gradle dependencies.
Also be aware that Google is not going to continue supporting Eclipse development. The tools for building Android application in Eclipse will not continue to receive updates, so bugs may pop up in the future that prevent you from continuing to use it effectively.
My second question is, if I'm using eclipse to make an app, will it be run on new devices too, as the project structure is different in eclipse and android studio.
The output of building an Android application is the same regardless of how or where you build it - you get an APK with the same file structure. The structure of the built APK is independent of the structure of the source code.
My final question is how can I use libraries from android arsenal if I don't use android studio (all the libraries there are for maven and gradle)?
Eclipse can use both Gradle and Maven for building. If you want to use libraries as Gradle or Maven dependencies, you will need to set up your project to use either Maven or Gradle to build instead of Ant. Otherwise you can still find JARs for most projects that don't rely on the Android framework, or you will need to get the source code for the library and set it up as a project dependency yourself.
