Technically, breezer is correct and I think the regulations you may find useful are the 'Electricity Supply Regulations'.
In reality, what your friends say is probably true. Lot's of people do pull the fuse, including me. I have never had any come back, BUT I am a competant person AND I can produce verifiable certificates to prove that the installation is safe. Can you? Those certificates don't necessarily apply just to the work you've just carried out, but also on other parts of the installation.
The board's opinion will depend on who looks at the meter. I've been handed 2 dozen meters before by an LEB operative and he's come back a week later and sealed them all up. No inspections, certificates or anything else.
Other times I have had checks carried out, all of which have been fine. Whilst you think it's an easy job (true enough within reason), do you know what they will be looking for when and if they do inspect? How's your main bonding? How's your main earthing conductor? Are those conductors correctly sized according to the supply arrangements? Are all the circuit conductors within the board sized according to their protective device? What about your tail size? Are you aware of the requirements for tails? Just because 'that's how they've always been', it doesn't make them safe and acceptable. If you find yourself wondering about any of the answers to these and many other questions (I won't go into any more) then I wouldn't even bother trying.
Many people do pull the main fuse, many people also drink and drive. It doesn't make it right and it doesn't mean you'll never be caught. You might be lucky , but I would strongly advise anyone who is i) not competant, ii) not aware of the requirements and iii) not aware of the consequences, not to even try it.