This is an old post and there may be a Qing Wen on it but yes "instead of" is a very very tricky thing to do in Chinese. 代替 替代 反而 and just 而 make it quite a challenge. An episode on this would be very welcome. I fell like I can express this idea clearly sometimes but it is a serious brain twister to be able to seamlessly execute sentences like:
"why are we riding bikes in the rain, let's just take the bus instead." I am not sure you would even use any of the above mentioned for the best translation of this sentence. You would probably be best just tagging 更好 on the end of it.
"instead, why don't we just look it up on the internet."
"instead of driving there, let's fly."
"I would rather eat spaghetti instead."
All of those stand the chance of being completely different. A Qing Wen on this would be very welcome.