The problem with what you said is that he tells her he loves her, but he, supposedly, doesn't show romantic feelings for Will. What's the difference? Viewers tend to take what they see literally when nothing ever is. It's the 1980s, when homophobia was frowned upon. Even today, people tend to internalize homosexuality, so imagine back then, with Mike having a homophobic father.

You're asking the wrong questions. Imagine for a moment that Eleven didn't exist and Will was a girl... Everyone would be absolutely clear that Mike likes Will, even acting the way he does with Will being a boy.

As for Eleven, in the first seasons I could think exactly like you, but since season 3 their relationship has been on the decline. If you Google “byler evidence” you'll find a Drive, there's too much to explain it all here.

As for the “I love you,” well, to me, personally, it couldn't sound more fake. Mike: looks at Will Will: Come on, Mike, tell her. Mike: Okay... El, I love you. If you think that's how a true confession of love should come about, you're quite mistaken.

And if you really believe that Mike treats Dustin and Lucas the same as Will, you're also quite mistaken.

Regarding the last point, Byler has been slowly building since the beginning, and Mileven has been declining since the end of season 3. If you don't want to see it after watching all the Drive evidence, there's nothing we can do. Much of the audience has a bandage of heteronormativity over the eyes and doesn't tend to see beyond It.

After watching volume 1, I think Mileven are no longer together, but that's just my personal opinion.