Every airshow accident has a negative impact on aviation that far outweighs a thousand successful demonstrations. If there is a fatality to the pilot then even more so, and if to the public then you can expect the hammers of hell to come down. Flying it to the wire will eventually bite you, but how much margin should you leave? Whatever you thought before has proven to be not enough and I guess it will now be decided for you by the CAA.
I'll judge that from the frequency of airshow accidents in the UK this year, that whatever airshow guidelines are published do not have an adequate safety management system to match the expectations of our absolute safety culture. ACAS on this side of the Atlantic has struggled with similar demons. I could add specifically that there are issues with low level jet work, but there was also the David Jenkins crash earlier. Expect the CAA to come down hard, and rightfully so - they are culpable for not acting sooner and instead now having to explain how their regulations resulted in public fatalities.