I've done a fair bit of driving on the right. I had a car when I lived in Germany a couple of years back and have been back around there since in a UK car. Also took our LHD VW van to Belgium. Then I was driving on our USA/Canada trip last year. I find I adapt pretty quickly, but some junctions can be challenging. Managed to get a puncture on that last trip, but we just got it fixed (in a different Bedford!). Having an automatic reduces the issues a little.
How did the locals drive? When we were in Spain driving carefully up the mountains the locals would overtake us. Hire cars must take a battering, but I tend to take a load of pictures to prove I didn't cause existing damage.
I hope the holiday was enjoyable, but I saw elsewhere you had some bruises from falling over.
Most of the 'locals' were pretty tolerant. The only thing they didn't respect was the zebra crossings. It was like Death Wish 2000, as they seemed to think pedestrians had no right to cross roads. About the only thing we noticed was that they had no fear and would overtake four cars and a coach on a blind bend.
That 'blind fear' may have some link with religion and thinking it's all in god's hands.
The Croatians did respect crossings and stopped for me.