RHD stick to LHD Auto was no problem when the roads are sooo big in the US. Would not like to have tried it the other way around first off - I can see why Americans are a little intimidated over here 'till they get their feet - roundabouts FTW.
Never drived a RHD car before, thought if driving it in a RHD proper road, what's difficult about it? Everything's the same, except you're doing it the other way around it.
I drive both; learning lefty is best started with an auto for those from RHD countries (at least, it worked for me). But there really isn't a huge problem; just getting your (left/right) hand used to doing something different.
I never tried RHD, but I imagine it shouldn't be too hard to drive the car (I have shifted from the passenger seat, meaning with my left hand). It's probably harder to navigate on the "wrong" side of the road. Strangely, RHD and left-side traffic IMHO is the right way to design a traffic system. That means I have watched too much British TV, I guess.
Both. The first time I drove RHD, it was between Heathrow and Birmingham in 2004. I had a Hertz brand new Ford Fiesta, 1.4 manual. I took the first roundabout in the wrong way and at the first traffic light, I put the car in 5th and stalled a couple of times before I catched my mistake. After that, no problem. It is just a little bit more difficult to park.. particulary between a Lotus and a Porsche...
Never tried RHD but I've always wondered about what it would be like and I definately do want to try it some time. I doubt it would be very hard, just gotta get used to shifting with my left hand. Auto, I bet I could do it easily.
That said, anyone can hop in a LHD/RHD car and make a smooth transition. You shouldn't be allowed to drive if you can't drive a car with the steering wheel on the other side of the usual position.
I still shift better with my left hand though. I notice that I'm a bit more violent with gearchanges when using my wanking hand.
Both - the strangest thing with moving into the opposite of what you normally drive is changing all those small things that you do automatically - like mirror checks.