Well, back in the day you were supposed to be signalling and sword drawing and gun waving and so forth.
Maserati 250F had central throttle pedal with brake to the right. Stirling Moss had his rearranged to be "normal". Many pre-WWII cars had central throttle, too.
Lotus was right hand shift, BRM had left hand (British) shift. Not sure if even then they were doing clutchless upshifting so if you're just lifting the throttle and slamming it into gear it makes sense to have the dominant hand doing it. I drove a left hand drive car in Spain and changing gear with my right hand was only weird because I'm left handed.
You might think that was the reason, but plenty of right-handers will disagree. It doesn't take that long to get used to it, but I'd rather do it in a sim than in real life
I am British so drive rhd cars but have driven many lhd cars as well, also rh shift single seaters it does not take long at all to get used to it. Friend of mine has an original lhd Cobra, I have driven it on UK roads many times no problem at all after 15 minutes or so but I guess if its the first time you have ever done it, then it could be a little intimidating.
No, RHD cars are the ones where you're using your right hand to steer (requires finesse and strength) and your left hand to change gear (very much less important and requires little motor skill). As most people are right handed RHD cars are naturally safer Interestingly, cars in Sweden were already LHD before they made the change from driving on the right. Or maybe that was only some cars, bought more recently with future-proofing in mind.
Well, I usually drive on the left side, but I have tried with the right side and after half an hour I get used to it, but I prefer the left side