I checked the raw and yeah he's not saying spears are unsuited for combat, he's telling her to narrow it down to combat specifically.
「武器は何を使う？」
"What kind of weapon(s) does she use?"
「魚を獲るときには槍を使ったことがあるそうです」
"Apparently she's used a spear when catching fish"
「それは銛では？」
"Does she mean a...
I'd feel better about it if he actually was aware of her antics and turning them back around on her, then I could at least say that they deserve each other.
For what it's worth:
「すまぬ」
apologies
「タイトル」
(on the) title
「ワンッ！！ワンッ！！」
bark! bark!
「異常ナシッ！！」
no abnormalities!
「小？？ ハッピー」
(couldn't make this part out) happy
「ショートコント」
short skit
「ポポヌョ狩り」
Poponyo Hunting
It's not parsed as [じゃパン]と[ポテトチップス] but rather [じゃ][パンとポテトチップス]. The じゃ just means "then" in the sense of "alright then" or "in that case". It's a less formal derivative of では.
But yeah, if you like japan puns:
https://yakitate.fandom.com/wiki/Ja-pan
Nothing like that happens again and the author has desperately backtracked on that character; it's been a really cozy series ever since. It feels like she was just trying to demonstrate how demi cultural norms might be totally different from human ones, but all of the readers are humans, so.