Hi shocking,
As you say there are so many regs, but this is hardly surprising as the jobs we do are really quite complex. I guess the best way to look at is that provided you have complied with the safety aspect, then you should be ok. There are a lot of good books out there which do help clarify what BS7671 is saying and this can help.
In truth it would appear that it is only when something happens that the regs are challenged by the laws. We use the regs as a defence in that if we have complied then we are working correctly so this is why people can be very picky on how close they work or install to the regs.
I used to teach short and full courses in BS7671 and was always amazed on how the same regulation could be looked at in so many ways. The best advice I can give is dont lose any sleep, just keep in there and hopefully making a good living.
Best wishes,
Rex