Mew and Top both saw each other as conquests. Trophies, if you will. Top was on a mission to deflower and seduce the virgin, to prove he is irresistible and able to get even the most "chaste" person. Meanwhile, Mew's plan was to domesticate the playboy, tame the most desired guy on the scene.
One was a mission of sexual submission and the other was a mission of romantic submission. Both their missions were derailed by genuine feelings of love and affection that arised, which confused both of them. At the end, Top got what we was seeking out at first, but it wasn't the power move he once expected, because he is down bad. And Mew also got Top's romantic affection, but couldn't "tame" his lover's sexual habits. Now both have had their egos bruised and are haunted by their own insecurity.
Sure, they played each other and it was a push and pull game from the jump. But, like every other character and storyline in the show, their predicaments and emotions are much more complex than a simple cat and mouse manipulation.
I don't believe the theory that Mew was a mastermind of a huge conspiracy. I believe his plan was about turning Top into a monogamous lovebird, which is just as much a power flex as Top's plan of being Mew's first lover was. Their push and pull was both a game of genuine seduction and a power struggle.
That saying bears repeating: everything is about sex, except for sex - sex is about power.
For me, the main reason is that because a lot people watch Only Friends for the mess, so they expected all the characters to be messy and toxic.
Then we have Mew, someone who hates messy stuffs in the middle of all the mess around him. And for me, that's his charm.
Mew is someone with amazing self-control, self-aware, and he knows how to handle unexpected situation without having to lose control.
We have seen him controlled situation where if it was another character, they would definitely lose their shit. But it's Mew, he refused to lose control in any situation which makes some people think he's boring.
For examples:
Episode 1
He made it clear that he wasn't ready for sex (where some people see him as someone who's playing hard to get and pretending to be naive). That's when I started noticing that he's someone with great self-control and knows when to set boundaries.
Episode 2
Top asked him to be his boyfriend and we had no idea that he was actually super embarrassed and dislike the idea of being asked out in public until he told us himself. In this one, he showed us that he was able to control his expression in an unexpected situation.
Episode 3
When that random stranger came to him and Top, openly flirted with Top right in front of his face, he didn't make it big, he didn't even show any kind of emotion. Imagine if it was someone like Ray? Nick? Boston? Oh, they would definitely lose their shit and make scene. Pretty sure Mew was actually uncomfortable and hate to be in that situation, but then again, it's Mew. He won't let his emotion make him lose control over himself.
In my opinion, the reason why he made that checklist and haven't officially date Top is because he want to make sure everything won't get messy (knowing what kind of person Top was in the past)
I personally think he's the most complicated character, for now he's the only one who hasn't shown any real emotion so I'm excited to see what kind of person he will become once he show us his real emotion.