But how much is the suit nerfing them? Could be reducing their mobility by 10x, could be by 5%. And don't forget the prize question:
Trunks thinks that the costume is nerfing them by over 50x. Listen, I didn't write this scene, it is completely ridiculous. Trunks can be wrong. He should be able to completely tank everything 18 has and finger flick her to death. I DID NOT WRITE IT. But the costume is far more restrictive than you are giving credit to. You are imagining that 18 vs Trunks goes exactly the same as 18 vs Trunks on Goten's shoulders. While Trunks directly disputes your assertion. You can't disregard character statements that are so important here. Think about how much you are factoring in the costume into your claim. Zero percent is the answer.
She's smiling because she figured out who the mystery fighter was. She had no idea who this strong dude is, why he was so weirdly shaped and didn't understand what was going on. The Super Saiyan transformation is what made it all click. This is not the evidence you think it is and you won't even agree with your own point because you have the boys somewhat rivaling 18 anyhow. Which would mean 18 would know that somewhat rivaling range boys going Super Saiyan should omega death kill her. Your own points are contradictory, you should be arguing 18 >>>> Base Boys if you think that smile thinks what you think it does.