Location of fuseboard

The regulations have changed considerably since 2005. Basically all new boards have to be metal and ALL circuits have to have RCD protection. When yours was done RCD protection would have been provided for all circuits apart from lighting. You do not have to change it, UNLESS you are going to have any major work done to your property, especially the lighting circuits which would require a certificate. This is because the electrician must ensure that it complies with the current regulations. As for the location, it sounds awkward, but again no you do not have to move it. In the end it is for an electrician to make judgement calls to comply with the current regulations, that's what we study for.

Whilst it might not be ideal, and wouldn't comply with modern regulations, probably lack of RCD protection on some circuits, which, depending on the consumer unit fitted, could be resolved by replacing some of the MCB's with RCBO devices The regulation in particular pertaining to height of switching and accessories is more to do with convenience than safety. The main thing to be concerned about from your description, is accessibility for maintenance and testing. IF it were to be moved, the DNO would normally fit an isolator between your meter and consumer unit which would then allow an electrician to alter the rest, but depending on the route and length of the cables used to do this, a fuse and RCD MAY have to fitted which can open a whole new world of issues. If someone has told you it has to be moved, and has to be replaced, I would get a second opinion, there is always the perfect, and often some middle ground

Without looking, it's very difficult to give you any guidance on this. There are so many variables that may come in to play that you should probably just ask an electrician to have a look. Many electricians will come and look at no cost and tell you what you need. If you can get two electricians to give you an idea then great.