You don't have to always test all of the above, as I've said before, it's not always practical nor helpful. I think too many people blindly follow the book without actually thinking about what they're doing and why.
I would recommend omitting the L+N test, on circuits with sensitive electronics or devices which can interfere with the test, and just test L+N to earth, you can use 1000V if you like, anything should be able to stand up to that, otherwise it's not safe.
As I said before, it's extremely unlikely something is shorting from live to neutral because there's normally two pieces of insulation between the two line conductors and it would more than likely just blow a fuse if there was a short. Think about it, in order for the live to short to neutral, two piece of cable need to be damaged, two conductors need to have worked loose from the terminal blocks or a piece of swarf needs to be connecting two terminals in just the right place. Think about how unlikely this is. There's far more chance of either or both conductors coming into contact with the earth conductor than directly each other. The part of the circuit most vulnerable to a direct live to neutral short is inside the lamp ballast or an incandescent lamp itself which you don't even try to test because you can't do it.
Why are you doing the testing anyway?
Is it a new installation? If so the fittings shouldn't have bulbs in anyway.
If you're modifying an existing installation you only really need to test the modifications.