I'd have to disagree. Remember the audience is supposed to be made up of an equal amount of males and females. So if they made the star character a girl and had a drawn out love story like the first series, some of the guys watching would feel like the show may be leaning towards a "girly" side. So they balled up all the romance and stuffed it in one episode to get it out of the way to focus of the more action oriented stuff in the future that the male audience wants to see.
tl;dr: Don't worry, the writers know what their doing.

Exactly i have full faith in the writers to keep it engaging. This was a pivot point, probably a way to put the kibash on the romance as a key point in the story for a few episodes. I expect to see more of a transition to her training and Imon in the coming episodes, with the tournaments matches being used to break up the main theme of the episodes until a single episode is dedicated to the climax of the Pro bending timeline.

But I would say it was rather surprising that the romance developed so quickly as a plot point in light of how they handled Aang and Katara, But again, thats proabably the point of the early tension.

I suppose the writers haven't failed us yet so it isnt hard to trust them.

The difference between Aang kissing Katara and Korra kissing Mako is the fact that Korra is 16/17-years old. She's supposed to be thinking about boys at that age and acting weird.

I think that was the point of it.

Umm no. If all he did was over hear her say that to Mako he'd just be a little upset. She went on a date with him, led him on, and made him think she was or would be his girlfriend before making out with his own brother right in front of his face.
SO not the same reaction!