It would even be an enhancement if you could search (CTRL+F) in the SQL tab :-)
Also the SQL Developer Exchange would be a good place to post this idea.
I can offer you an alternative that you can try right away - and I wouldn't argue with your assessment of the view editor today - try the data modeler.
The view editor there is much more powerful, and you can click around other places while you craft your query or make your changes. It also offers a query builder to help you with the query if you want.