Re: over sea displays. Yacht masts. Wasn't it Dartmouth? Anyway, how low do you have to fly to hit a yacht mast? Is that height reallly necessary? For me, that statement raises more questions than answers.
Yes, the birds might be a risk but raise the display a little and have a BCU plan and that should help mitigate that risk. However, the biggest risk is when there is a poor horizon, making 'the goldfish bowl' effect. However, this can also be managed with raising display heights.
I think the appettite for Air Shows, especially the smaller ones on MoD sites, was down to imsurance. The MoD don't tend to insure and so a big accident like the tragedy at Shoreham will cost the MoD a lot of money and a big loss of reputation - so in balance someone has probably decided it isn't worth it (rightly or wrongly).
LJ