Sarah: I think you have to maintain a sense of proportion as to how much you can cottonwool people such that they are completely safe under all circumstances. For a nonagenarian such as your friend, you would need to ban people running, fat people with shopping baskets taking up lots of room, other nonagenarians and octagenarians unsteady on their feet who might fall into her, all cracks in all paving, and so on, the list is endless.
Cyclists and pedestrians can share the same space if they use a bit of commonsense. One would certainly expect cyclists to dismount and push their velocipedes if the pavements are crowded. As with everything else, it is the bad eggs who spoil it for the rest.
I would urge Howard to walk about wearing a camera titfer to record instances of cyclist indifference to pedestrians as per the cyclist's YouTube video below recording a bit of pavement rage. Perhaps the bad eggs can then be brought to book and shown the error of their ways.
http://www.kentonline.co.uk/dartford_messenger/news/2011/july/25/attacker_on_youtube.aspx