I can't wait to dig in and read this since I too loved the ep, but I just wanted to comment on this because I keep seeing it mentioned

4. Um, could it have been any more obvious that Tom Welling can't ride? He could have at least sat on a horse, surely?

They generally won't let him anything that may result injury, and riding a horse can be dangerous and unpredictable and there's no way to write a Clark injury into the show, so they (from what I'm told) avoid having him do things like that. :) And he can probably ride being married to an equestrian, but maybe not.