Have you forgotten that DM did not,for once,ask where she was staying when she came to stay with him.She stayed in the store room,and did he do anything about it?
When Maulik started staying at the store room,Santu slept at the mandir.He came and asked her,why she was sleeping at the mandir,and wasnt she staying at the store room( which btw,was infested with rats and what not).She replied,since maulik is staying there,she had to sleep at the mandir.Which meant,he knew she was staying in the store room,and chose to do nothing about it.Even if she was moved to the guest room,it was because he started developing some feelings for her.If he didnt,probably he would kept on staying silent about it.
As for treating her in the right way.After she told him about how she handled Birwa's case,did you see how he listened to her,and then later on,just barked at her to leave the place.I dont know,i am just unable to find it appealing.And neither would you,if you know what i am talking about.
This,to me,definitely means that he was very well cruel,again,as you said,in his own way,even if it was not physical torture.Which again,he has inflicted on her once,for no fault of hers.
I didnt say Subhi was not happy with him,i only said that we cannot say for sure.Also,we can judge a person from the way he behaves till now,and that hasnt been so enchanting.Atleast not for me.