No it's not normal.As far as regulators mounted backwards are concerned, I remember diving in the Azores 2 years ago, with a British guy, BSAC certified, who mounted his first stage that way.
Seeing my surprise, he told me it was standard BSAC procedures. We dived only once together so I've never figured he was kidding or not. Has anybody here BSAC experience and can confirm or not ?
I was forced to configure my setup the 'wrong way round' because the hoses coming out of the 1st stage snagged the tank. On my first trip to Florida back in the early 80s, I had a 'helpful' crew member try to change things; I ended up getting free dives that day for fear I was going to sue the operator for interference. I had no such intention, I just laughed, the skipper jumped to the wrong conclusion.