You make several good points that I had been considering as I live in a very large "gun free zone"... the UK!
Even a handful of coins thrown at someones head will make them duck or try to dodge... puts them off their aim. You might, if you carry a bag, have an old steel tray that happens to fit exactly inside of it. it will certainly stop a knife of machete attack if used as an improvised shield. Might also stop or defect a hand gun bullet of the type used in the shopping mall attack in Germany recently. You might carry a few tools in your car that can be used as weapons... of course you never even think of them as weapons... that is practically hate crime in the UK... they are tools only... coughs.... or a multi tool in your pocket at all times... small scale stuff I know but in the UK our choices are very limited indeed.
The day has come when the “The Art OF Self Survival” is a MANDATORY course in our schools. I am not suggesting this be taught, I am demanding it be taught. Very simply tactics when/if applied as others have suggested, would certainly reduce the numbers killed versus what we have seen when NO RESISTANCE is put forth against those who would do us harm. Wake up people, this is REAL.
UK citizens are in a tough place.
The old American saying is ‘better judged by 12 than carried by 6’.
If you have to use improvised weapons always ‘stab stab stab’ vs ‘stab’. Feel free to add 20 more to the first sequence.
Even something that will not penetrate is better than nothing; after all, bruises hurt too. Bruises on bone hurt more.
Even small dog bites hurt. As the old saying foes; ‘It is not the size of the dog in the fight, it is the size of the fight in the dog’.
You will not get the fight you want but you must do your best with the fight you get (an old Marine told me that).
If they confiscate them, you're out the equivalent of no more than a couple of pounds if that. You would want to show extreme shock and surprise at the thought that a simple piece of plastic pipe for your home could be a weapon.