I know the manga you are referring. It's just the author, slowing down the story progression. I can overlook not figuring out a way to communicate with the animals as his thinking is still constraint to our world. But like you said, the demi humans exposes this issue.
It's seem like it, but if the king still had his magic stone intact, it would have taken more time. He has been in power for so long and would have not let it happen without everything he got. The results could also be more devastating.
I did find this arc less interesting than previous ones. It was a bit too long for my taste. I do think this chapter was one of the better ones of this arc.
Why doesn't he want to show off? If he likes to drive his Countach so much, he should have offered to drive his boss. Now, he missed a perfect opportunity to seal the deal fast.
After reading some works, this one included, were the harem is properly made, started thinking more positively about it. The issue is that most anime/manga that we get exposed have a bad harem realization. Where the girls start throwing them selfs at the MC for the smallest thing. From which...