I agree with you when you say: 'The only way obedience to God can be taken too far is if it's not God you are obeying.'
but the dilemma is made apparent when you say this:
'As mere humans, we do not always know when we are doing something out of love or out of other motives.'
If you think about it, haven't just as many crimes been perpetrated in the name of 'obedience' as in the name of 'love'?
I could then take your first statement and change it like this:
'The only way love can be taken too far is if it's not really love.'

You are favouring one word over another: both of them perfect words when understood but that's the problem anyway: understanding them, so its kind of circular. If youth does everything out of love (real love) of course he'll be fine but if Robert had used the word 'perfectly obedient to the will of God' that is love anyway isn't it? The question is how is Youth going to know what either of these words really mean except by trial and error in his own life? - just like the rest of us I guess . . . .