Day run is probably best. My lights have been f**king up again turning on and off randomly. Need to do another bodgey fix on them.
I will address the second part of your post when I get home lol.
Keen for birthday party.
Different profile tyres on the front wheels would cause a difference in rolling diameter. Even if they are the same profiles all round there would still be a difference due to the fronts being skinnier than the rear.