Does it matter if one of my tyres has a different load rating?

Due to having had a puncture we now have a 95V rating tyre whereas all the remaining three original tyres are 91V. Is this illegal or dangerous? The supplying dealer says this is causing tyre pressure...

I can't find an all-season tyre with a high enough load rating, would this affect my insurance?

My handbook says my tyre's load rating should be 96 but I want to fit 4 season tyres and I cannot find a supplier who has anything above 94. Would it affect my insurance if I fitted 94?