That is way to complex and unneeded!

You need to do as said above, measure the draw at the battery first, with an amm/multi meter.

I can't see exactly what you are trying to achieve by checking fuses?

It seems a common problem with these, in fact a woman at work recently had the same trouble (Petrol powered though) I was going to have a look at it for her but then she changed the car instead, she did say though they had someone look at it and he said it was an ECU drain and it would be expensive to fix, I am sure it can't have been that serious!

Martin