Here's the thing. I've always been complaining about this from the start, not just now. The lack of realism is the greatest flaw of this show.

First of all, why does Izuku ever turn off his full cowling? Was there ever a drawback established from keeping it on?

About violence, did you not listen to the part about how the vibration dude just shattered earth to separate the UA students and everyone reacted to it saying "people might have gotten seriously injured?"

About not grabbing and kicking... Is it a better option to just slap a hand away and discuss confidential info vs grabbing and kicking and see what happens? Really..?

I also think Stain's abilities were bullshit. That's the point. The entire concept of people whose quirks don't strengthen their bodies competing with people whose quirks strenghten their bodies is nonsensical, and I've always been against that,