I kinda liked the contrast really. When his helmet is on, he acts like a cold, merciless sith lord. When it's off, he's just a petulant kid way over his head.

Considering that he rekt Lukes Jedi order, he pretty much IS a school shooter.

School slasher.

And I thought that was just crappy story. Maybe he IS that much of a weakling.

I thought he was really well cast, and that was the whole point - he's an angry kid playing at jedi. Yeah, he's scary to a trooper because even a padawan is tough to a normal dude, but he's not trained properly - and he knows it.

Sure, but I expected him at least to be a little more imposing for a "dark lord". His attitude, rank, and attire create some expectations (before he took his mask off).

He's not a dark lord tho. In case you didn't know that.

Mainly I wanted to say "main bad guy", but that doesn't sound as Star Wars-y.

But he's not the main bad guy. The BBEG is Snoke, while Ren is just his apprentice, and a ****** one at that. It's entirely apparent that Snoke is the antagonist, given that in the Original trilogy Sidius isn't even introduced until the final movie, and is only barely mentioned before that. In the new new trilogy, Snoke is introduced practically at the very beginning, and even though he is never physically seen in-person, it can be assumed that the reason everyone is afraid of pissing him off is because he can kill them from wherever he is hiding.