LOL! If I had a dollar for everyone who claimed this proves Sola Scriptura! "Thoroughly equipped" doesn't mean it EXCLUDES anything else! Also, Eph 4:11-13 talks about another way of perfecting the Christian - and the Bible is not even mentioned...
Rev. 22:18-19 : 18 I warn everyone who hears the words of the prophecy of this book: If anyone adds anything to them, God will add to him the plagues described in this book. 19 And if anyone takes words away from this book of prophecy, God will take away from him his share in the tree of life and in the holy city, which are described in this book.
This attempt to use this as a closing for the ENTIRE Scripture corpus is pretty lame, considering John wasn't writing the last book of the Bible when he wrote it! He is referring ONLY to Revelation's prophesies, not other books.
Regards
2 Tim. does not exclude anything else, it excludes anything else EXTRA. So, if I taught orally, right from the Bible, that would be good. Sola Scriptura does not mean that the only way to get good information is to read it directly by yourself. Teaching from the Bible is good. Speaking of this, your Ephesians passage means what I just said in this context, that teaching is good. It certainly does not imply to teach outside of what is now the Bible.
If you believe that MORE is needed, besides scripture, then you must believe that "thoroughly equipped" is not good enough. What can Tradition add to "thoroughly equipped"?