We have had to have double fire exit, no smoking, 4 meter cupboard safety signs, told to remove framed, glazed pictures from the walls, remove plants on set back shelves and around the main entrance. The property is occupied by 4 pensioner couples who don't want to feel as though they live in an institutionalised old folks home, or a fire safe

Can't plant pots be secured so they won't fall off? Can't framed pictures be screwed to the wall so they can't be knocked off the wall? We feel it's not our home anymore. It' regulations gone mad!

Looks like an overzealous manager

A guide to making your small block of flats safe from fire (accessible) - GOV.UK

4 Fire Hazards

Housekeeping

Good housekeeping is fundamental to reducing the risk from fire in the common parts. The common parts should be kept clear of any combustible materials or storage.

There should be a zero-tolerance approach, in which residents are not permitted to use the common parts to store any belongings or dispose of rubbish.

However, in well-managed, secure blocks, it is often acceptable to permit items of lower risk in the common parts, such as doormats, pot plants and pictures on walls.

That's rather excessive - you don't need fire exit signs in simple single stair single exit buildings & glazed framed pictures and plant pots (as long as the plants are kept watered and alive) are not usually a real hazard (I'm usually happy with them).

Smoking signage is an explicit legal requirement with no get around - however the requirement for it to be at least A5 with specified text was dropped (in England) years ago so a simple 75mm or 100mm no smoking pictogram by the entrance would suffice
Other signage can and also should be sympathetic - for a typical plant room or meter cupboard there are two ways of signing them that are compliant - one of which is less institutional