As with anything, after you start practicing you stop making beginner mistakes. If you switch to Emacs or Vim today, you are going to typo things that Eclipse would have auto-corrected for you. That's because you've never practiced typing correct code from memory. But use Emacs or Vim exclusively for a month, and you'll see that you are much better at programming than Eclipse is. You'll write code more quickly with fewer errors.

Also, using autocomplete to explore APIs is one of the worst programming practices I can think of. The docstring for one method is not nearly enough information to tell you why you should call the particular method of the particular class that autocomplete suggested. In order to be sure you've made a good API use decision, you need to read the documentation and code for the library, and then decide to use it. Anything else is a hackish shortcut that will surely waste more of your time than it saved.

And, if you can't remember the names of methods you know you want to use, maybe it's time to refactor. Or practice remembering. If you want to be bad at programming, Eclipse will make your life slightly easier. If you want to be good at programming, start programming and stop commanding an autocomplete tool.

Code completion, syntax validation, and built-in API documentation are useful features. To say they're things that only beginners or bad programmers use is absurd. I have much better things to do with my time than memorize the exact name and parameter order of every method in an API.

I primarily use Vim as my IDE, so I'm not saying I prefer Eclipse or other IDEs. But I don't pretend that Vim is perfect and using an IDE is a sign of inability.