school me on wood stoves.

what is diff about design that makes them EPA Cert, and would(pardon pun) that matter if installing in my house somewhere in flyover country? Will I need permits if I live in a Gun Rights state? If I do some construction that requires inspection for other reasons, will some Inspector flag my recently installed Wood Stove?

I thought they got Cat Converter to cut pollution and that also greatly increased heat, but don't see that in any current model mentions.

How important or not is a window? Should a rookie like me get a window model?

These guys mention a Cat and its some "hybrid".
https://www.woodstove.com/ideal-steel-hybrid-wood-stove

Are they all like that, with secondary pre-heated air like these? https://www.woodstove.com/ideal-steel-hybrid-wood-stove

Would blowing on a wood stove with normal household fan greatly increase heating and why don't I see that?

What about Picrel that also functions as an oven with thermometer?

I see goofy fans that attach to double walled flu, but why not just bore some big holes at top and bottom of outer flu?

Instead of outer flu, why not a bunch of fins?