I don't know if he will stop doing this because we're not really sure if the uke was bothered by it, I personally think he was angry when he was in front of the mirror just because his other clients might be unwilling to touch him in this state.
I think so too, for me if either the uke loves him or is only interessed in the money and will leave him craizy it's fine
I don't know if we can call it love so soon. For now, the seme is just a top-class client with a lot of money and influence. So yeah as you said the uke is only doing this because of money. I just hope that the seme won't force his love on him..
The fact that he performs strangulation might be a way for him to mark his "territory" and "possess" his lover.
To my mind, he is the type of man who needs to feel his lover within his reach, that's all. In the second chapter, he was insecure and worried that he would left him and be "out of his reach".