Can I use crispy rice cereal instead of puffed rice?

Yes, you totally can. The texture will be different though - crispier and less airy. I've done it in a pinch when my health food store was out of puffed rice. Just know they'll be more like classic rice crispy treats texture-wise.

Are these gluten-free?

They can be, Puffed rice is naturally gluten-free, but always check your peanut butter label (some brands process nuts in facilities with wheat). For certified gluten-free versions, Bob's Red Mill puffed rice is my go-to.

Absolutely, My niece has a nut allergy, so we make hers with sunflower seeds instead. You can also just leave them out entirely - the peanut butter gives plenty of protein on its own. The squares might be slightly less crunchy though.

Why won't my treats stick together?

Oh honey, I've been there. Usually it means you didn't press hard enough or the peanut butter-honey mixture wasn't warm enough to coat everything. Next time, really pack it in there like you're mad at the pan.