The differences in priority rules tick me off way more than the side of the road.
A lot of people say changing gear with their right hand feels more natural. To be honest I don't think there is a lot of difference. If you're a competent driver the position in the he car shouldn't make for much difference.
However, the oddest thing is that when returning to Australia I now find something like 90% of cars (excluding 4WDs) are automatic, so no changing of gears. While in Europe, the majority of cars are still manual.
I do often turn on the windscreen wipers, when I mean to use the indicator, regardless of which country I'm in.
The secret is to have an absolute position pattern in your head - you know that first gear is up and to the left - and your brain is able to operate your hands accordingly. Same as how you learn where the cupboards are in a kitchen and can open them no matter where you are standing - you have an absolute mental map of the kitchen.
It's probably because driving is a stationary activity that the brain develops a relative map (move right hand this direction) rather an absolute (first gear is over there)
Modern autos are actually more efficient than manuals, and easier to drive. The market has spoken.
The wiper stalk position varies depending on the car. As I pretty much only drive European cars it's always on the left and not an issue.
As for switching between LHD and RHD, you'll have a default. When stressed (heavy traffic, bad weather etc) your brain will be overloaded making decisions and you will use your default. If that doesn't match the car you're in, you'll try and change gear with the door handle. It's just mlike crossing the street, the way you first learnt is burnt in, and while you can override that, one day the basic programming comes back to the top and you look the wrong way and step out.
It must be quite a danger driving on both sides of the road, take care.