Banner blindness to the rescue!
I actually agree with all the points you made - I just don't have a good solution at the moment. In particular, locking a language indefinitely could have an impact on the unlocking of words. Will update here if I come up with something.
Edit: you can now set the language to persist across levels - follow the instructions in the tooltip.
I have to say I agree with alion here, it would be nice to disable the code window entirely. As he mentions this is quite impressive, but it is also quite distracting. For me personally it does not contribute to the fun of the game in any way, and I can't say I would care much if I wouldn't unlock any words. I don't mean to be offensive in any way, just trying to give you my honest thoughts.
It definitely seems to be quite an improvement in terms of usable screen real-estate :D
If your goal is to not hinder the unlocking of words, it might not be a bad idea to remove the 'visible' constraint on unlocking them since they are currently almost always off screen.
Also, I think this is a bug, but everytime I refresh, it seems like the game thinks I have zero unlocked words and they pop off until I've collected them all again (which is a bit distracting also :P)
