More complete overview below, but basically, it can move faster through phases, can’t be judged as well by color, and can reach crack at lower temperatures. It’s totally possible to get a great outcome! Dialing it in is the fun IMO Link

Decaf beans are harder to roast well (IMO) so it tends to be that the mass distributed ones won’t be great since they’re in less demand. You can find small locals that do decaf runs sometimes, or order green beans and do it yourself. Remember, darker means less caffeine, so if you’re pulling medium roast beans and have no good decaf source, try something dark that you can tolerate and see whether it helps

Yep, exactly! Single origin is fun and all, but roasters know that blends make for a more consistently well rounded cup. Blending batches is even a thing between different roasts of the same bean. If you enjoy the taste, it’s always the right call!

For what it’s worth, wetting paper filters is usually done with near boiling water in the chemex, so it IS preheated with the regular process. Preheated steel also won’t retain as much heat. I don’t disagree with your post as written, it just doesn’t match the reality of what’s usually done