Killer too obvious?

i didn't think so

Yes

One thing's for sure, the actor playing the killer had a lot of fun once revealed, especially when delivering the "No leftovers!" line.

They tried it so hard to make it like it was Booby until the end. Baseballs falling around when the "unknown" killer was chasing Kathleen in the old house's cellar (Bobby was a pitcher) and the most obvious one, when everyone is strapped and at the table, when the killer goes for Evan he says "You're going to break the Internet", a reference to the beginning of the film where he brags about the fight with the other team's dude and saying that that "Shit would have broken the Internet" if it had been recorded. Only the people in the car at that moment could have known about what Evan said, and Bobby was there.

Yes because the killer wasn't very big, which narrowed it down to two choices.

the only problem is that it does not seem possible that the Killer could have had the opportunity to do the killings during the parade and definitely not during the dinner table scenes. seems like the killer would have had to been in two places at the same time.

I don't see it. The obvious choices were Bobby, and Ryan. Or maybe even Mitch based on motive. The only real clue was that he walked up to the house in first person in the opening scene.

There's a massive, massive spoiler in the first 30 seconds of the film if you're familiar with Friday the 13th. Other than that, no, it's fairly unpredictable because the reveal makes absolutely no sense and can't really be predicted. Calling it a stretch would be a stretch.