Honestly, there are many things that are unnattractive in this manga and I'm really dissapointed, because there are some things that are very entertaining.
First thing I found really strange is how the MC behaves at times. Although not all of the time, he seems really awkward and childish. For example, when he was deciding how to sleep with his first slave and when he wanted to 'help' the slave merchant with the thief. Am I the only one that though it was kind of a stupid chapter overall. The thief was low level, his comrades had already died and his target was too big even if he had 4-5 guys more.
Another thing that I find really annoying is the information that he shares with his party members. I mean selective sharing is a very good idea, but sometimes it comes off as dumb, because he decides to leave his party members confused about small things. For example, they already know he can equip multiple jobs, one of them knows that he can change the jobs of the other person and that his sword is considered very powerful by most standards, but he decides to not tell them about the MP depletion side effect when the dwarf uses fusion.
My man the girl got depressed and looked really pitiful, I think that explaining something so little could atleast alleviate some of her worries. For me, this just shows how inconsiderate the author is while writing his story. Even parts of the 'romance' seem really uncomfortable, because of how the characters behave and respond to things.
About the romance, it is mostly the MC that makes it feel really uncomfortable, because he seems to be trying to use parts of that word's logic. He seems to treasure his slaves in a way, but he never expresses anything beyond the fact that they are his property. He never talks long enough with them to explain that he actually considers them more than just party members and slaves. No matter how much sex you have with someone, that does not mean you love them, you also need to talk with them and demonstrate your love wholly.
I mean the MC was a depressed guy in his previous life, wouldn't he become very attached to someone who shows him affections. Wouldn't that make him really determined to become something more to them, not just their master... I don't get the point in presenting MCs with depressive backgrounds, only to make them out like very average or over the top characters without any development.