Some Sentences with New Words

With this word "envy," it means to be jealous of. To be insolent is to be rude. So you would not want to envy a rude/insolent person. I would replace the word "envy" with perhaps, "detest."

2) Don't pay attention to when he often frowns while speaking with you. He just wants to hide his kindness because he knows people tend to abuse it.

3) We panted as we reached the top of the mountain. It was really hard to get there.
4) I observed a small commotion on the street yesterday, when my neighbor's ancient car drove out of the garage. People were really astonished while viewing this unusual raucous and the kids immediately surrounded the scene.

"Ancient" can be used here but it sounds a bit strange to call the car ancient outside of metaphorical speech. I replaced "rarity" with unusual raucous (loud noise/s) because you described a commotion earlier in the text. 

5) I prefer to drink soothing tea tonight. It will help me fall asleep faster.
6) The railway station is halfway between my home and the company I work for.
7) I like being by the river. It refreshes me.