Can I use another IDE such as NetBeans or IDEA to develop eclipse plugins?
It is not recommended. Eclipse provides a plugin development environment (PDE) and one of its key features is the creation of a specific type of launch configuration that allows plugins to be both run and debugged against a target platform. This configuration, commonly known as a runtime-workbench, launches your target platform plus any development plugins you have in your workbench. It would be difficult, if not impossible, to set up another IDE to do this.